Pls help this is for my semester exam

This graph shows the melting and boiling points of the alkali metals. Think about Francium, do you think it would have a higher or lower melting/boiling
point than lithium? Why? Can you predict it from the data?

Pls Help This Is For My Semester ExamThis Graph Shows The Melting And Boiling Points Of The Alkali Metals.

Answers

Answer 1

The melting point of francium was thought to be around 8.0 °C (46.4 °F); Additionally, 27 °C (81 °F) is frequently encountered. Due to its radioactivity and extreme rarity, the element's melting point is unknown. 20  1.5 °C (68.0  2.7 °F) was the result of a different extrapolation based on Dmitri Mendeleev's method.

Why is francium so soft to the touch?

There are additional electron shells as you move down any group—for instance, Lithium has two shells and Francium has seven—that result in electron shielding. The force of attraction diminishes as it travels further through these shells to the outermost one, resulting in less powerful bonding.

Why do alkali metals have lower melting and boiling points?

The weaker each metallic bond becomes, the lower the melting and boiling points become. The iotas in a metal are kept intact by the fascination of the cores to electrons which are delocalized over the entire metal mass.

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Related Questions

in general, real gases behave most ideally at pressures and temperatures. the behavior of real gases can be described using the van der waals equation

Answers

Molecule move quickly at high temperatures & low pressures. These intermolecular attractive forces diminish as a consequence, and the real gas starts to behave like that of an ideal gas.

What is an example of ideal gas?

Many gases, including gas, oxygen, hydrogen, noble metals, some denser hydrocarbons like atmospheric co2, and combinations like air, can be classified as ideal gases if certain parameters are kept within reasonable bounds over a wide range of temperatures and pressures.

What is the ideal gas worth?

Whenever the pressure is expressed in kPa, the real gases standard is found to be 8.314J/Kmol. The pressure, quantity, temperature, & number of molecules of an ideal gas are all related by a single equation known as the ideal gas law.

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what is the name of (CH3CH2)2COHCH3​

Answers

The name of the compound (CH3CH2)2COHCH3 is butane-2,3-diol.

The compound is an alcohol, which means it contains a hydroxyl (-OH) group. The prefix "butane-" indicates that it has four carbon atoms in a straight chain, and the suffix "-diol" indicates that it contains two hydroxyl groups. The prefix "2,3-" specifies the positions of the hydroxyl groups on the carbon chain.

Butane-2,3-diol is also known by other names, including 2,3-butanediol, 2,3-dihydroxybutane, and 1,4-butanediol. It is a colorless, viscous liquid that is used in the production of plastics, solvents, and other chemicals.

The name of (CH3CH2)2COHCH3​ compound is butane- 2,3- diol.

What is butane- 2,3- diol ?

The organic substance 2,3-butanediol has the formula (CH3CHOH)2. It falls under the vic-diol category. It exists as a chiral pair, three stereoisomers, and a meso isomer. All liquids are colorless. Precursors for various polymers and insecticides are examples of applications.

A butanediol with hydroxylation at C-2 and C-3 is known as butane-2,3-diol. It is a secondary alcohol, a glycol, and a butanediol.

Among its many possible uses are the production of printing inks, perfumes, synthetic rubber, fumigants, antifreeze agents, fuel additives, foodstuffs, and pharmaceuticals. 2,3-Butanediol (2,3-BD) is a promising bulk chemical.

Alcohols classified as primary have just one alkyl group on which the carbon atom of the hydroxyl group (OH) is connected. These major alcohols include, for instance, ethanol, methanol (propanol),

Thus, The name of (CH3CH2)2COHCH3​ compound is butane- 2,3- diol.

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Mitochondrial conditions determine the degree of reduction of each carrier in the respiratory chain. For example, when NADH and , are abundant, tlu steady-state degree of reduction of the carriers decreases as electrons pass from the substrate too, When electron transfer is blocked, the carriers before the block become more reduced and those beyond the block become more oxidined. Match the state of oxidation for ubiquinone (C) and cytochrome, 1.6,4, and as with each mitochondrial condition. Abundant NADH and Oy, but cyanide added only canken under de los contented. Abundant NADH, but o, exhausted All wien werden All card Abundant o, but NADH exhausted Biarly care dorproduto ou come mai bine Abundant NADH and O2

Answers

All transporters were reduced as cytochrome oxidation is inhibited by cyanide. Since there is no terminating electron acceptor when O2 is absent, all carriers undergo reduction.

Who or what is an electron?

A negative charges particle known as an electron can be either independent or attached to an atom (not bound). Another of the three main types of elements within an atom is an electrode that is bonded to it; the other couple are protons & neutrons.

What gives electrons their energy?

An electron's energy is determined by where it is in relation to the atom's nucleus. The distance an electron inside an atom has to travel from the nucleus depends on its energy level.

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If we represent the equilibrium as:
CoCl 4

2−
(aq)⇌Co 2+
(aq)+4Cl −
(aq)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is decreased the equilibrium constant,
K
: increases. decreases. remains the same. More information is needed to answer this question. 3. When the temperature is decreased the equilibrium concentration of
CoCl 4

2−
: increases. decreases. remains the same. More information is needed to answer this question. At high temperature the red color is strong. At low temperature the gas has less color. If we represent the equilibrium as:
2NO 2

(g)⇌N 2

O 4

(g)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is decreased the equilibrium constant,
K
: increases. decreases. remains the same. More information is needed to answer this question. 3. When the temperature is decreased the equilibrium concentration of
N 2

O 4

: increases. decreases. remains the same. More information is needed to answer this question. At high temperature the red color is strong. At low temperature the gas has less color. If we represent the equilibrium as:
N 2

O 4

(g)⇌2NO 2

(g)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is increased the equilibrium constant,
K
: increases. decreases. remains the same, More information is needed to answer this question. 3. When the temperature is increased the equilibrium concentration of
N 2

O 4

: increases. decreases. remains the same. More information is needed to answer this question.

Answers

For a first reaction its exothermic reaction ,increases, decreases.

For second reaction its exothermic reaction, increases, decreases.

For third reaction its endothermic reaction , increases, decreases.

What principle underlies Le Chatelier?

Le Chatelier's principles, sometimes known as the equilibrium law, allow for the prediction of a system in chemical equilibrium (such as the change in temperature or pressure).

The equilibrium position moves to the right at low temperatures.

Please see the accompanying file for a more thorough explanation.

CoCl₄²⁻ (aq)  ⇆ Co²⁺ + 4Cl⁻

1. Exothermic -

At low temp, the position of equilibrium shifts to right side and forms more pink color.

when the temp decreases. the K increases

[tex]K = \frac{[Co^{2+} ][Clx^{-} ]^{4} }{CoCl_{4} ^{2-} }[/tex]

2. At low temperature, more Co²⁺ produces and K values will increase as equilibrium shifts towards right.

Higher [Co²⁺] = Hugh K value

3. When temperature decreases the concentration of CoCl₄²⁻ decreases.

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the addition of hbr to some alkenes gives a mixture of the expected alkyl bromide and an isomer formed by rearrangement outline the mechanism of formation and strcutres of products form the reaction of hbr with

Answers

Alkyl halides are produced by adding HBr to alkenes.The pi bond of the alkene functions as a weak nucleophile & reacts with electrophilic proton of HBr, which is a helpful way to conceptualize the reaction.

How intermediates are involved in the bromination or alkene and what is the reaction mechanism?

A 3-membered ring intermediate is produced as a result of the alkene acting as a nucleophile in this reaction and attacking the electrophilic bromine.The carbon that is most capable of stabilizing positive charge then is attacked from of the back side [akin to a backside attack inside the SN2 Mechanism] to produce the trans product.

Which one of the following statements accurately describes how an alkene and HBr react when peroxide is present?

The free-radical mechanism governs the addition reaction with HBr to an asymmetrical alkene inside the presence of peroxide.Here, an alkene interacts with a bromine radical to make an anti-Markovnikov product.

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To make oxygen free the copper is heated in an atmosphere of hydrogen.
Explain how this will remove the oxygen.

Answers

Answer:

When copper is heated in an atmosphere of hydrogen, the hydrogen gas can react with the oxygen present on the surface of the copper to form water. This reaction is known as reduction. The equation for this reaction is:

2H2 + O2 → 2H2O

In this reaction, the oxygen atoms in the copper are reduced (i.e., they gain electrons) and the hydrogen atoms are oxidized (i.e., they lose electrons). As a result, the oxygen is removed from the surface of the copper, leaving it oxygen-free.

This process is often used to purify copper and remove impurities, such as oxygen, that may be present on the surface of the metal. It is also used to produce high-purity copper for use in electrical and electronic applications, where the presence of oxygen can affect the conductivity of the metal.

∆Hrxn for a particular chemical reaction is –85 kJ. Which of the following is true?

A. The reaction releases energy as it occurs, and the energy level of the products is less than the energy level of the reactants.
B. The reaction absorbs energy as it occurs, and the energy level of the products is less than the energy level of the reactants.
C. The reaction releases energy as it occurs, and the energy level of the products is greater than the energy level of the reactants.
D. The reaction absorbs energy as it occurs, and the energy level of the products is greater than the energy level of the reactants.

Answers

The energy level of the products is lower than the energy level of the reactants, and energy is released throughout the reaction. (Option A)

What is meant by an exothermic reaction?

Chemical processes known as exothermic reactions generate heat. When heat is transferred from the system to its surroundings, as described, the heat flow q is considered negative. Therefore, the H of reaction is negative for exothermic reaction processes.

Why is exothermic reaction negative?

Therefore, a reaction is exothermic and its enthalpy will be negative if it releases more energy than it takes in. Consider this as a certain quantity of heat evaporating from (or being removed from) the reaction. Endothermic reactions have positive enthalpies because they absorb or use more energy than they produce.

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Which of the following macromolecules is the most chemically stable, and can potentially survive in the rock record for millions or even billions of years? O Lipid RNA DNA Polysaccharide point Which of the following macromolecules can BOTH store information in sequence of nucleic acids AND potentially act as catalyst for biochemical reactions? Protein Polysaccharide Lipid DNA 0 RNA

Answers

1)Unlike other macromolecules, lipids can survive in rock records for millions or billions of years. This is typically used for rock quantification.

2)RNA is both a nucleotide acid and a prospective catalyst.

Macromolecules are largely polymers, which are long chains of molecular divisions known as monomers. Long polymers are found in carbohydrates, proteins, and nucleic acids. They are classified as macromolecules due to one‘s polymeric nature as well as large size. Macromolecules are massive molecules that populate cells and provide vital functions for life. Macromolecules, for example, offer structural support, a source of non - renewable power, the ability to store and collect genetic information, and the capacity to accelerate biochemical reactions. Lipids are fatty substances that serve numerous functions in your body. They are part of your cell membranes and help control what enters and exits your cells.

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If you had a closed jar with a fish and a plant in it, explain where photosynthesis and cellular respiration are each happening

Answers

Answer:

Photosynthesis would happen in the plant, while cellular respiration would happen in the plant and the fish. In the plant, photosynthesis occurs when light energy is converted into chemical energy used for growth and development. In fish, cellular respiration occurs when the fish takes in oxygen from the water and uses it to convert energy from food into usable energy...

Explanation:

which of the following statements is (are) true? correct the false statements it is impossible to satisfy the octet rule for all atoms in xef

Answers

The first and third statements are correct, impossible for every atoms in xef to satisfy this same octet rule.

What is octet rule?

The octet rule is a general chemical principle that represents the idea that main-group elements have a propensity to connect in a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

TRUE

The octet rule is not followed by Xe. In fact, it creates ties. It can accommodate more than 8 electrons.

Since Xenon has valence electrons at the fourth energy level, it can reach the fourth sublevel, which gives it access to more than eight electrons. The Xenon is surrounded by 3 lone pairs and 2 bonded pairs of valence electrons in XeF2, which is dsp3 hybridised. The VSEPR forecasts the form to be linear.

The d sublevel is not accessible to elements in the first two periods of the Periodic Table, and they are instead required to abide by the octet rule (or duet H and He rule).

False. (b)

Due to its electrical arrangement of 1s2, 2s2, and 2p4, oxygen is tiny and does not have a vacant d-orbital.

(c) TRUE

Stronger bonds result from stronger bond orders. The bond strength will also be lesser the longer the bond is. One can tell that the NO+ bond will be stronger if they compute the bond order, which is greater for NO+ and the bond length, which is greater for NO-.

D. FALSE

Due to Covalency, the three oxygen forms are bonded. The double bond and single bond will switch places if you design a resonant structure, but in reality, no resonating form can fully explain the structure of ozone; the behaviour of the bond is the average of a single bond and a double bond between the oxygen atoms. There is neither a weaker nor a stronger bond in ozone because both bonds are equivalent.

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For a particular process, q = 25 kJ and w = –15 kJ. Which of the following statement(s) is/are true?

A. Work is done by the system on the surroundings.
B. The temperature of the surroundings increases.
C. The internal energy of the system increases.
D. The process is exothermic.
E. Statements A and B are true.
F. Statements A and C are true.
G. Statements C and D are true.

Answers

For the given question, statements A and B are true. So, Option E is correct as the work done given is negative.

How to calculate the work done with respect to the surroundings?

According to the First Law of Thermodynamics, energy can only be changed from one form to another through the interplay of heat, work, and internal energy. Under no circumstances can energy be created or destroyed. It can be represented as:

ΔU = q + w

where,

ΔU = Total internal energy of the system

q = the heat that is transferred from a system to its surroundings

w = work done on the system or by the system

It is given in the question that q = 25 kJ and w = -15 KJ

So we get from the above equation-

ΔU = 25 - 15 = 10 KJ

The negative amount of heat that the environment has absorbed will be the value of internal energy.

Thus, the negative sign of work done shows that the work is done by the system on the surroundings while increasing the temperature of the surroundings.

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Below, energy is plotted as a function of reaction progress for a catalyzed and uncatalyzed chemical reaction. Assign the terms to their corresponding features in the figure. Which curve in the plot represents the catalyzed reaction? O the blue (top) curve O the green (bottom) curve

Answers

The green bottom curve represents the catalysed reaction.

It is common practise to use catalysed reactions to quicken a particular chemistry's progress. The catalyst's main function is to offer the reaction a different, lower-energy pathway.

In a catalysed reaction, the reactant molecules readily pass the activation energy barrier and produce products. As a result, the activation energy of an uncatalyzed reaction is higher than the activation energy of a catalysed reaction.

For catalyzed reaction activation energy lower than uncatalyzed reaction. The complexity of the collisions necessary to reach a transition state means that without the catalyst, the Ce4+ ions and Tl+ ions must directly react in a termolecular reaction, which will be substantially slower.

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Read the temperatures shown to the nearest 0.5°C
Answer: 37.0 and 42.5

Answers

The temperatures shown to the nearest 0.5°C is 42.5°C.

What is temperature?Temperature is the measurement of the coldness or hotness of a substances or object  or place.The instrument used to measure temperature is termed as Thermometer.

°C (Celsius):

°C (Celsius) is the measurement of Temperature on the Celsius scale .This is one of the S.I systems of temp. measurement.The other scale used to measure Temperature is Kelvin scale.The units of °C (Celsius) is marked on the thermometer as shown in the image.0°C (Celsius) is equal to 273.15 K

Hence, as per the given image the temperatures shown to the nearest 0.5°C is 42.5°C.

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Why sulphuric acid is used in preparation of chrom alum ?!?

Answers

Answer:

it act has a catalyst

Explanation:

sulphuric acid is a catalyst that is used in the preparation of chrom alum

What is the volume of a 1.25 M solution
if it contains 42 grams of sodium
hydroxide.
Volume NaOH = [?] mL

Answers

Answer:

You could calculate the answer given the formula

M = mol/L

you can get mol using g/MolarMass

=> 42g/22.99g/mol = 1.82688125mol

1.25M = 1.82688125mol/V

=> apply simple algebra
V = 1.4615 L
=> Notice that the answer requires the unit to be ml
V = 1.4615L * 1000ml/L = 1461.5ml

=> Notice that the given grams have 2 sig figs

V = 1500 ml

Magnesium reacts with hydrochloric acid in a sealed container, as shown. The initial pressure inside the container is 1.20 atm and its volume is 100 mL. What is the pressure inside the container after 243 mg of magnesium has reacted? (Note: Assume the reaction is isothermal and the gas behaves ideally.)
Mg(s) + 2HCl(aq) â MgCl2(s) + H2(g)
(30 degrees celsius)

Answers

3.6 atm is the pressure inside the container after 243 mg of magnesium has reacted.

In plain English, what is pressure?

Pressure is defined as the force applied perpendicularly to an object's surface divided by the area over which that force is applied.

The reaction given is: Mg(s) + 2HCl(aq) → MgCl2(s) + H2(g). The moles of H2 gas formed are therefore equal to the moles of Mg that reacted, and can be calculated from: n = 0.243 g/(24.3 g/mol) = 0.01 moles (converting 243 mg to 0.243 g).

The added pressure is calculated by P = nRT/V using approximations: 0.08 L atm/molK for R (0.0821 rounded), 300K for T (303.15 before rounding) and 0.10 L for V.

Solving gives pressure = 2.4 atm. Finally, this number must be added to the initial pressure: 2.4 + 1.2 = 3.6 atm.

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Carlos rides his bike away from the school at a constant speed. Explain what a
distance-time graph for this type of motion
would look like.

Answers

The slope of a distance-time graph for this motion will have a straight line to represent that the object in motion is at a constant speed.

What is a distance-time graph?

A distance-time graph depicts how far an object has traveled in a specified amount of time. It is a simple line graph that depicts distance versus time findings. The Y-axis represents distance. On the X-axis, time is plotted.

The slope of the distance-time graph should always be constant because the bike is moving at a constant speed. As a result, the graph will be a straight line through the origin.

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Which of the following compounds contains both ionic and covalent bonds?A SO3B C2H5OHC MgF2D H2SE NH4Cl

Answers

The bonds ionic and covalent are in the NH4Cl as it has the one ionic bond and 3 covalent bonds.

There is definitely a coordinate bond (that's definitely a type of covalent bond wherein handiest one of the collaborating atoms donate each in their electrons to shape a covalent bond) among lone pair of nitrogen in ammonia(NH3) and a proton(H+ ion),which as a result creates an ammonium ion(NH4+).

Further this ammonium ion because of a high quality fee bureaucracy an ionic bond with chloride ion(Cl–).So definitely there are:-3 natural covalent bonds in NH3.a coordinate bond(which is likewise a covalent bond) among NH3 (ammonia)and H+ ion(proton).And of route an ionic bond among NH4+ (ammonium ion) and Cl–(chloride ion).

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The unit cell in a certainlattice consists of a cube formed by an anion at each corner, ananion in the center, and a cation at the center of each face. The unit cell contains a net: Question 8 answers
5 anions and 6cations
5 anions and 3cations
2 anions and 3cations
3 anions and 4cations
2 anions and 2cations

Answers

Lattice structures: The correct answer is 2 anions and 3 cations. The unit cell contains a net 2 anions and 3 cations

What are lattice structures?

A lattice structure is a unit cell that fills all available space and may be tessellated along any axis without any spaces between the cells. These structures are a new development in terms of weight, energy, and time savings in modern manufacturing.

Anions are present at 8 corners and in one corner contribution is 1/8

so for 8 corners =(1/8)×8=1

And one anion i at centre and its contribution is one

total anion=2

Cations are present at 6 corners and contribution of one face is 1/2

So, net number of cations is 6×1/2 = 3 cations.

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The unit cell contains a net 3 cations and 2 anions.

Lattice structures: what are they?

A unit cell that completely occupies its area and can be tessellated along any axis without any gaps between the cells is known as a lattice structure. In terms of weight, energy, and time savings in modern manufacturing, these structures represent a new advance.

Corner atoms are counted as 1/8 of a total atom (just 1/8 of them are inside the unit cell's boundaries).

Atoms in the center count as one whole (whole thing inside the unit cell)

Face atoms are counted as one-half of a unit cell (half inside, half outside).

Therefore, the computation for anions is

1/8 anion at each corner x 8 corners on a cube = 1 anion

+ 1 whole anion

 = 2 anions per cell

The formula for cations is

1/2 cation at each face x 6 faces on a cube = 3 cations per cell

The unit cell contains a net 3 cations and 2 anions.

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C=3×10(8)m/s, 1eV=1.6×10(-19)J , RH=1.079×10(7)m-1, 1nm=10(-9)m, 1A°=10(- 10)m, h=6.63×10(-34)J.s
The radioactivity A of a drop of iodine I-131 if the mass of the drop is 1.5 g and the period is 13h is:

Answers

The radioactivity A of a drop of iodine I-131 if the mass of the drop is 1.5 g and the period is 13h is:  1.29 x 10^(-11) disintegrations/second.

What is radioactivity?

Generally, To find the radioactivity of a drop of iodine I-131, you will need to use the following formula:

A = (N/M) * ln(2) / T

where:

N is the number of atoms in the sampleM is the atomic mass of the isotopeln(2) is the natural logarithm of 2T is the half-life of the isotope

To use this formula, you will need to know the atomic mass of I-131, which is about 130.906 amu, and its half-life, which is about 8.04 days. You will also need to convert the mass of the drop from grams to atomic mass units, which can be done by dividing the mass by the atomic mass of carbon-12 (12 amu).

First, convert the period from hours to seconds:

13 hours = 13 * 60 minutes/hour * 60 seconds/minute

= 5,040 seconds

Then, convert the period from seconds to days:

5,040 seconds = 5,040 seconds / (24 hours/day * 60 minutes/hour * 60 seconds/minute)

= 0.6 days

Then, calculate the half-life in seconds:

8.04 days = 8.04 days * 24 hours/day * 60 minutes/hour * 60 seconds/minute

= 691,840 seconds

Then, use the formula above to calculate the radioactivity:

A = (N/M) * ln(2) / T = (N/130.906 amu) * ln(2) / (691,840 seconds)

= (1.5 g / 12 amu) * ln(2) / (691,840 seconds)

= 0.125 * ln(2) / (691,840 seconds)

= 0.08867 * (1/691,840 seconds)

= 1.29 x 10^(-11) disintegrations/second

So the radioactivity of the drop of iodine I-131 is approximately 1.29 x 10^(-11) disintegrations/second.

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Which of the following has the largest percent by mass of carbon?
a. CaCO3
b. CO2
c. NaHCO3
d. CH4

Answers

The largest percent composition by mass of carbon is d)CH₄ .So,correct option is d.

We need to calculate the molecular mass of each of the compound and then check how much by mass carbon is present in the compound.

a)Molecular mass of calcium carbonate (CaCO₃) is =40+12+3ˣ16=100g

Now,we know that carbon has molecular mass=12g

So,percentage composition of carbon in CaCO₃=(12/100)ˣ100=12%

b)Similarly,molecular mass of carbon dioxide (CO₂)=44g

So,percentage composition of carbon in carbon dioxide is =(12/44)ˣ100=27.27%

c)Molecular mass of Sodium bicarbonate(NaHCO₃)=23+1+12+3ˣ16=84g

So,percentage composition of carbon in NaHCO₃=(12/84)ˣ100=12.85%

d)Molecular mass of methane(CH₄)=12+4ˣ1=16g

So, percentage composition of carbon in methane=(12/16)ˣ100=75%

We can see that by mass largest amount of carbon is present in methane(CH₄).

Hence,correct option is d.

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(Complete question) is:

Which of the following has the largest percent by mass of carbon?

a)CaCO₃

b)CO₂

c)NaHCO₃

d)CH₄

Another sample of eggshell reacts completely with 4.0 mL of an HCl(aq) solution of unknown concentration. If the reaction produced 0.095 atm of gas, the concentration of the HCl(aq) solution was at least (A) 0.0020 M (B) 0.050 M (C) 0.50 M (D) 1.0M

Answers

The concentration of the HCl (aq) solution was at least 1.0 M.

What is concentration?

The abundance of a constituent divided by the sum of the mixture's volumes is the definition of concentration in chemistry. There are several different categories of mathematical description: mass concentration, molar concentration, number concentration, and volume concentration

P = 0.095atm(corresponds to 0.20g of CaCO3

so,moles of CaCO3 =0.20g/100gmol⁻¹=0.002moles

moles of HCl =(molesₓCaCO3ₓ2)=0.002ₓ2

M=0.004/4ₓ100

Concentration of HCl=1M

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A tumor marker is being developed to detect early breast cancer. Of the 400 women who volunteered for the study, 350 tested negative for the marker. Of these women, three developed breast cancer. The 50 women who tested positive for the marker underwent further tests, of these 50 women, 48 were diagnosed with early breast cancer, and the other two women were found to not have breast cancer. Use enclosed excel sheet for your answers (including your calculations)

Answers

While tumor marker test results can be useful, they are not conclusive. A low result does not imply that you do not have cancer or that you are in remission.

CA 15-3, for example, is raised in less than half of patients with early breast cancer and in more than 80% of those with metastatic breast cancer. Three tumor markers, cancer antigen 15-3 (CA 15-3), cancer antigen 27.29 (CA 27.29), and carcinoembryonic antigen (CEA), have been used in breast cancer care to help monitor metastatic breast cancer (advanced disease), but they have not been found to be useful in detecting a breast cancer recurrence or extending lives. If the level falls, the treatment is effective. If it rises, the cancer may be spreading.

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the cloth shroud from around a mummy is found to have a 14c14c activity of 10.0 disintegrations per minute per gram of carbon as compared with living organisms that undergo 16.3 disintegrations per minute per gram of carbon. part a from the half-life for 14c14c decay, 5715 yryr , calculate the age of the shroud.

Answers

Shroud's vintage t=4.28×10 3yr If the cloth veil from a mummy has a 14C14C energy of 10.0 disintegrations for minute per kg of carbon in comparison to live things that experience

What exactly is state disintegration?

When a government is no longer in effective control, the third component necessary for a state to exist, state structures appear to fall apart. Diverse regions of the nation's borders may be affected by this at varying intensities.

t = k1 ln N 0N t t = - dfrac 1 1.21 times 10-4 text year 1 ln dfrac 9.7 16.3

t=1.21104 yr1 1 ln 16.39.7 t = 4.28times 103 textyr

t=4.28×10 3 yr

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Which of the following reactions releases most energy to the surroundings?
A Reaction energy change = -456 kJ
B Reaction energy change = +547 kJ
C Reaction energy change = -38 kJ
D Reaction energy change = +1456 kJ
Also give reason

Answers

The Reaction energy change = -456 kJ releases most energy to the surroundings. Option A is correct here

What is a chemical reaction?

In a chemical reaction, one or more substances—also known as reactants—are changed into one or more additional substances—also known as products. Chemical elements or chemical compounds make up substances.

Chemical reactions are the processes by which a substance or substances change chemically to create a new substance or substances with entirely new attributes. The most energy is released into the environment via the reaction energy change, which is -456 kJ.

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Which of the following accurately describes minerals? A) When a food is burned, all the minerals are found in the ash. B) The body absorbs each mineral from foods in much the same way. C) Minerals in food can be destroyed by acid. D) The body needs about 200 milligrams of each trace mineral each day. E) Major minerals are more important than trace minerals.

Answers

When a food is burned, all the minerals are found in the ash. Therefore, the correct option is option A which  accurately describes minerals among all the given options.

What is mineral?

A mineral is unique from its synthetic analogues, which must be generated through natural processes by definition. Artificial minerals, such as emeralds, diamond, sapphires, and other expensive gemstones, are routinely made in industry and scientific facilities and are frequently almost similar to their biological counterparts.

There are thousands of known mineral species, with around 100 of them constituting the primary dissolved minerals of rocks; they are known as rock-forming minerals. When a food is burned, all the minerals are found in the ash.

Therefore, the correct option is option A.

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Rank the compounds in each of the following groups in order of increasing acidity or basicity, as indicated, and explain the order you assign. (a) acidity: HCl, HBr, HI
(b) acidity: NaHSO3, NaHSeO3, NaHSO4
(c) basicity: Mg(OH)2, Si(OH)4, NaOH
(d) acidity: HF, H2O, NH3, CH4
(e) acidity: HOCI, HOCIO, HOCIO2, HOCIO3

Answers

The compounds in each of the following groups in order of increasing acidity or basicity, as indicated are basicity: Mg(OH)2,NaOH and Si(OH)4.

The base MgOH are more weaker as compared to that of the NaOH as these are really less in electronic configuration and has the lowest electrons in NaOH is eventually more stronger than all bases as it has the best conjugation basics property that defines the basic structure and strength.

The NaOH is stronger among all as it is having higher basic properties that's fir the basicity of any base. The Si(OH)4 are the basic that has the lesser basic properties than that of the NaOH and MgOH.

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a sample of carbon dioxide gas collected at a pressure of 204 mm hg and a temperature of 298 k has a mass of 59.9 grams. the volume of the sample is l.

Answers

After solving the equation the volume of the sample is 121.967L.

What is ideal gas equation?

The Ideal Gas Law (also known as the General Gas Equation) states that the pressure, volume, and temperature of an ideal gas are related through the equation PV = nRT, where P is the pressure, V is the volume, n is the number of moles of the gas, R is the ideal gas constant, and T is the absolute temperature. This equation is useful for understanding the behavior of gases and for calculating the amount of gas present in a given volume at a given temperature and pressure.

Using ideal gas equation

PV=nRT

V=nRT/P

n=59.9/44 =1.361 mol

V=[ 1.361×62.3636LmmHg/Kmol×293.15K]÷ 204 mm hg

=121.967L

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The volume of the sample is 121.967L.

Define the ideal gas law.

The ideal gas law, also known as the perfect gas law, is a relationship between a gas's pressure P, volume V, and temperature T in the range of low pressures and high temperatures where the gas's molecules move virtually independently of one another.

The ideal gas law (PV = nRT) connects the macroscopic characteristics of ideal gases. An ideal gas is one in which the particles are both non-repellent and non-attractive to one another (have no volume).

Using ideal gas equation

PV= nRT

V= nRT/P

n= 59.9/44 =1.361 mol

V=[ 1.361×62.3636LmmHg/Kmol×293.15K]÷ 204 mm hg

=121.967L

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The energy change for an electronic transition in a one-electron atom or ion (H, He+, Li2+, etc.) from n initial to n final is given by delta E = -(2.18 times 10-18 J)(Z2)(1/n2 final - 1/n2 initial), where Z is the atomic number. Which one o f the following species will have the longest wavelength emission line for the transition between the n initial = 2 and n final = 1 levels? O H O He+ O Li2+ O Be3+
O B4+

Answers

H will have the longest wavelength emission line for the transition between the n initial = 2 and n final = 1 levels.

A movement (or leap) of an electron from one energy level to another within an atom or artificial atom is referred to as an atomic electron transition. It seems discontinuous because the electron "jumps" from one quantized energy level to another in a matter of nanoseconds or less.

Electronic transitions occur in atoms and molecules as a result of electromagnetic radiation absorption or emission (typically UV or visible). Planck's equation, E = h, relates the energy change associated with a transition to the frequency of an electromagnetic wave. Transitions between these permitted orbits occur in photon absorption or emission. A photon is released when an electron transitions from a higher-energy orbit to a more stable orbit.

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Arrange the following gases in order of increasing density (hlghest denslty at the bottom of the list) under the conditions given. Assume that the volume of the contalner Is not fixed. Place these In the proper order: Hellum at 1atm and 273 K Neon at 2 atm and 73 K Neon at 1atm and 273 K Neon at 2 atm and 273 K

Answers

Helium in 1 atm + 273 K, neon at 1 atm, neon at 2 atm, neon at 2 atm, and neon at 73 K

Who or what uses neon?

Advertising signs are the main application for neon gas. High voltage indicators are also made of neon, and helium-neon lasers are created by combining neon with helium. As a cryogenic refrigerant, liquid neon is employed.

What makes neon so scarce on Earth?

Neon is extremely volatile and doesn't form any compounds that would allow it to be fixed to solids, which accounts for its relative paucity on Earth as well as the inner (terrestrial) planets. As a result, in the early Solar System, it broke free from the planetesimals while being warmed by the newly ignited Sun.

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