Answer:
After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M.
Explanation:
Based on the reaction of the problem, you have as general kinetic law for a first-order reaction:
ln[HI] = -kt + ln [HI]₀
Where [HI] is actual concentration after time t,
k is rate constant
and [HI]₀ is initial concentration of the reactant.
Initial concentration of HI is 0.310M,
K is 0.0660s⁻¹,
And the actual concentration is 0.0558M:
ln[HI] = -kt + ln [HI]₀
ln[0.0558M] = -0.0660s⁻¹*t + ln [ 0.310M]
-1.7148 = -0.0660s⁻¹*t
26.0s = t
After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M
A hot needle sinks when put on the surface of cold water. Will a cold needle float or sink in warm water?
Answer:
sink
Explanation:
The Intermolecular force of attraction exists within the water molecule. This type of intermolecular force of attraction is known as a hydrogen bond. A hydrogen bond is a dipole-dipole intermolecular attraction that occurs when hydrogen is covalently bonded to highly electronegative elements of a small atomic size.
When the heat is applied to this intermolecular force, the heat disrupts the intermolecular force, and the surface tension is being broken. This is what caused a hot needle to sink when placed in cold water. But when a cold needle is placed on the surface of warm water, the cold needle will not break up the warm water's surface tension. As a result, the cold need sinks in the warm water.
Compounds and solutions are different because
A.only compounds are a form of matter.
B.compounds are pure substances while solutions are not.
C.a compound can be physically separated.
D.only compounds have uniform composition.
Answer:
only compound have uniform compositiob
Write 5 facts you know about weather and climate.
1) You can tell the temperature by counting a cricket's chirps! 2) Sandstorms can swallow up entire cities. 3) Dirt mixed with wind can make dust storms called black blizzards. ... 5) The coldest temperature ever officially recorded was -89.2°C.
What should the ^14_6C content (in percent of y0) of a fossilized tree that is claimed to be 3000 years old?
Answer:
The current mass fraction of [tex]^{14}_{6} C[/tex] should be approximately 68.8 percent.
Explanation:
[tex]^{14}_{6} C[/tex] is a radioactive isotope with a halflife of 5568 years. The decay of any radioisotope is modelled after the following ordinary differential equation:
[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex]
Where:
[tex]m[/tex] - Current mass of the isotope, measured in grams.
[tex]\tau[/tex] - Time constant, measured in years.
The solution of this equation is of the form:
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex]
Where:
[tex]t[/tex] - Time, measured in years.
[tex]m_{o}[/tex] - Initial mass of the isotope, measured in grams.
The time constant can be found as a function of halflife ([tex]t_{1/2}[/tex]):
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex]
If [tex]t_{1/2} = 5568\,yrs[/tex] and [tex]t = 3000\,yrs[/tex], the mass fraction of [tex]^{14}_{6} C[/tex] is:
[tex]\tau = \frac{5568\,yrs}{\ln 2}[/tex]
[tex]\tau \approx 8032.926\,yrs[/tex]
[tex]\frac{m(3000\,yrs)}{m_{o}} = e^{-\frac{3000\,yrs}{8032.926\,yrs} }[/tex]
[tex]\frac{m(3000\,yrs)}{m_{o}} \approx 0.688[/tex]
The current mass fraction of [tex]^{14}_{6} C[/tex] should be approximately 68.8 percent.
which of the following correctly described a compound
Answer:
We need the options to answer.
Explanation:
N/A
What kind of questions CANNOT be answered by chemistry?
Answer:
Why does matter exist?
Explanation:
What obligations do scientist have to society
Compound A, C7H13Br, is a tertiary alkyl bromide. On treatment with CH3CH2ONa, A is converted into B, C7H12. Ozonolysis of B with O3 gives C as the only product. What are the structures of compounds A and B
Answer:
Compound A: 1-bromo-1-methylcyclohexane
Compound B: 1-methylcyclohex-1-ene
Explanation:
In this question, we can start with the I.D.H (hydrogen deficiency index):
[tex]I.D.H~=~\frac{(2C)+2+(N)-(H)-(X)}{2}[/tex]
In the formula we have 7 carbons, 13 hydrogens, and 1 Br, so:
[tex]I.D.H~=~\frac{(2*7)+2+(0)-(13)-(1)}{2}=1[/tex]
We have an I.D.H value of one. This indicates that we can have a cyclic structure or a double bond.
We have to keep in mind that the Br atom must be bonded to a tertiary carbon. We can not have a double bond because in the ozonolysis reaction we have only 1 product, therefore, we can not have a double bond in the initial molecule (if we have a double bond in the initial molecule we will have more than 1 product in the ozonolysis reaction).
With this in mind, we will have a cyclic structure. If we have 7 carbons and we need a tertiary alkyl halide. We can have a cyclic structure of 6 members and a methyl group bonded to a carbon that also is bonded to a Br atom (1-bromo-1-methylcyclohexane).
In the reaction with [tex]CH_3CH_2ONa[/tex] we will have an elimination reaction. In other words, we have the production of a double bond inside of the cyclic structure (1-methylcyclohex-1-ene).
See figure 1 for further explanations.
I hope it helps!
Convert 355 km/s into mm/s.
Answer:
the answer would be, 355000 mm/s.
Atomic Structure and Bonding_quiz Q12 Points The principal, angular momentum, magnetic and spin quantum numbers for an atomic system are designated as nn, ll, m_lm l , and m_sm s , respectively. Which of the following statements is true?
a. nn represents the shape of the electron cloud
b. m_lm l represents the orientation of the electron spin an electron at n=1
c. n=1 classifies as a "free electron" ll represents the shape of an orbital
Answer:
ll represents the shape of an orbital
Explanation:
There are four quantum numbers which give information about various orbitals in an atom. They describe the probability of finding the electron in an atom.
The orbital or azimuthal quantum number is represented as l. This quantum number gives information about the shape of an orbital.
If this container of gas is heated,
then the pressure inside the container will
increase because pressure increases as
temperature increases.
Hypothesis
Theory
Law
Answer:
theory
Explanation:
kinetic theory of gases
Answer:
Hypothesis
Explanation:
Just did it
0.660 moles of NaCl are dissolved in 95.0 mL of water. Calculate the molarity of the NaCl solution. A) 62.7 M B) 0.069 M C) 6.95 M D) 0.0069 M
Answer:
C) 6.95 M.
Explanation:
Hello,
In this case, considering that the molarity is computed via the ratio of the moles of solute to the volume of the solution in liters:
[tex]M=\frac{n_{solute}}{V_{solution}}[/tex]
Since the volume here is 95.0 mL or also 0.0950 L, the molarity turns out:
[tex]M=\frac{0.660mol}{0.0950L} \\\\M=6.95 M[/tex]
Therefore, answer is C) 6.95M.
Best regards.
During your future endeavors in chemistry you will inevitably do a bunch of acid-base problems. Of the strong bases above, calcium hydroxide, strontium hydroxide, and barium hydroxide often trick students into making small mistakes. Why do you think that is the case? a. There is only half a mole of hydroxide per mole of compound. b.They are actually acidic rather than basic. c. Nothing special about these, all acid-base is confusing! d. There are two moles of hydroxide for each mole of these compounds.
Answer:
d. There are two moles of hydroxide for each mole of these compounds.
Explanation:
calcium hydroxide, strontium hydroxide, and barium hydroxide all have two hydroxide compunds. the difference between each of these compounds is they all contain a different element along with hydroxide.
Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4 NH3 + 5 O2 → 4 NO + 6 H2O When 40.0 g NH3 and 50.0 g O2 are allowed to react, what is the mass of the remaining excess reagent?
Answer:
18.75 g of NH3.
Explanation:
The balanced equation for the reaction is given below:
4NH3 + 5O2 → 4NO + 6H2O
Next, we shall determine the masses of NH3 and O2 that reacted from the balanced equation.
This can be obtained as follow:
Molar mass of NH3 = 14 + (3x1) = 17 g/mol
Mass of NH3 from the balanced equation = 4 x 17 = 68 g
Molar mass of O2 = 16x2 = 32 g/mol
Mass of O2 from the balanced equation = 5 x 32 = 160 g
From the balanced equation above,
68 g if NH3 reacted with 160 g of O2.
Next, we shall determine the excess reactant. This can be obtained as follow:
From the balanced equation above,
68 g if NH3 reacted with 160 g of O2.
Therefore, 40 g of NH3 will react with = (40 × 160)/68 = 94.12 g of O2.
From the calculations made above, we can see that it will take a higher amount of O2 i.e 94.12g than what was given i.e 50g to react completely with 40 g of NH3.
Therefore, O2 is the limiting reactant and NH3 is the excess reactant.
Next we shall determine the mass of excess reactant that reacted. This can be obtained as follow:
From the balanced equation above,
68 g if NH3 reacted with 160 g of O2.
Therefore, Xg of NH3 will react with 50 g of O2 i.e
Xg of NH3 = (68 × 50)/160
Xg of NH3 = 21.25 g
Therefore, 21.25 g of NH3 (excess reactant) were consumed in the reaction.
Finally, we shall determine mass of the remaining excess reactant as follow:
Mass of excess reactant = 40 g
Mass of excess reactant that reacted = 21.25 g
Mass of excess reactant remainig =?
Mass of excess reactant remainig = (Mass of excess reactant) – (Mass of excess reactant that reacted)
Mass of excess reactant remainig
= 40 – 21.25
= 18.75 g
Therefore, the mass of excess reactant remaining is 18.75 g of NH3.
Sort these molecules into the appropriate bin according to their polarity.Drag the appropriate items to their respective bins.HBr CO2 BF3 H2 CH4 NH3Polar Non polar
Explanation:
Generally, polar molecules contain polar bonds that arise as a result of the difference in electronegativities of the elements in the molecule. In most instances, molecules containing a metal and a non metal are polar in nature.
HBr - This molecule has two opposite sides of polarity, a group 1 and group 7 element. It is polar
CO2 - The bond between C and O is polar however, there is a cancellation of the polar bonds due to how the atoms are arranged. It is non polar.
BF3 - There is no net dipole (separation of charges) in this compound hence it is non polar.
H2 - Covalent molecules made up of only one type of atom are non polar.
CH4 - This is non polar as the difference in electronegativities between C and H is not great enough to form a dipole.
NH3 - The polar bonds (N-H) do not cancel each other out. Hence this molecule is polar.
100. cal of heat are added to 18.0 g of ethanol (0.581 cal/g °C) originally at 23 °C. The final temperature is ____________.
Answer:
Final temperature is 32.56 °C
Explanation:
The specific heat of a substance is the amount of heat required to raise the temperature of 1g of the substance by 1°C.
The following equation/formula is used;
Q = m × c × ΔT
Where; Q= amount of heat supplied
(cal)
M= mass of ethanol (g)
C= specific heat of ethanol
(cal/g °C)
ΔT= change in temperature (°C)
i.e. (final temperature - initial
temperature)
According to the question, Q= 100 calories (cal), M= 18g, C= 0.581 cal/g °C, initial temperature = 23°C, final temperature = ?
Hence, we insert our values into the equation;
Q = m × c × ΔT
ΔT = Q/mc
(Final T - Initial T) = Q/mc
(Final T - 23) = 100/ 18 × 0.581
(Final T - 23) = 100/10.458
Final T - 23 = 9.562
Final T = 23 + 9.562
Final T = 32.562
Hence, the final temperature of ethanol is 32.56°C
WORTH A LOT OF POINTS! just copy what on the picture for notes so i can copy and paste i do not feel like writing all of that down
Answer:
A base pair is a pair of bases that form hydrogen bonds in the double stranded DNA molecule.
- Adenine-thymine: A-T
- Guanine-cytosine: G-C
Replication Process:
- Double strand unwinds.
- New nucleorides line up via base pairing.
- Colvalent bonds link nucleotides together in the new strands.
Explanation:
What is the main purpose of a leaf
Explanation:
for respiration(exchange of gases)
Actually, all leaves have the same structure. The main purpose is to carry the photosynthesis out, that provides food that needs to survive. :)
Calculate the kinetic energy, in joules of a 1250-kg automobile moving at 20.0 m/s.
Answer:
250000 J.
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 1250 kg
Velocity (v) = 20.0 m/s.
Kinetic energy (K.E) =?
Kinetic energy is simply defined as energy possed by a body in motion. Mathematically, it is expressed as:
K.E = ½mv²
Where:
K.E is the kinetic energy
m is the mass of the object
v is the velocity of the object.
Thus, we can obtain the kinetic energy of the automobile by using the above formula as illustrated below:
Mass (m) = 1250 kg
Velocity (v) = 20.0 m/s.
Kinetic energy (K.E) =?
K.E = ½mv²
K.E = ½ × 1250 × 20²
K.E = 625 × 400
K.E = 250000 J
Therefore, the kinetic energy of the automobile is 250000 J
Under what set of conditions does HCl(g) deviate the most from ideal behavior?a) high temperature and low pressure.b) low temperature and high pressure.c) high temperature and high pressure.d) low temperature and low pressure. e) standard temperatore and pressure.
Answer:
b) low temperature and high pressure
Explanation:
Deviation of gases from their ideal behavior could be as a result of two things which include a very small volume for the gases and the collisions not being elastic enough.
Small volume will decrease the frequency of elastic collisions a gas will experience as a result of the tiny space.
Low temperature will decrease the amount of elastic collisions and energy of the gas and high pressure will decrease the volume which is why there will be a deviation in the ideal behavior of Hcl(g)
a person loses 2.70 lb in two weeks. how many grams did they lose?
Answer:
1224.7
Explanation:
Each lb is 453.59
Based on the conversion factor, a person loses 2.70 lb in two weeks loses 1225.8 g
How can we concer from pounds, lb to grams?The conversion factor from pounds to grams is given as follows:
1 pound = 454 gTherefore, 2.70 pounds can be converted to grams as follows:
270 lb = 2.70 × 454 g/ 1 lb
270 lb = 1225.8
Thus, a person loses 2.70 lb in two weeks loses 1225.8 g
Learn more about pounds and grams at: https://brainly.com/question/1121265
Which explains why mixtures can be separated
Answer: A: the components have different properties
Explanation:
The guy above is wrong I’m right got it correct on my unit review on edge
Answer:
A.
Explanation:
1. What are the 5 senses you use
during the 1st step Scientific
Method observation?
Answer:
Sight, hearing, taste, touch, and smell
Explanation:
A 194-g sample of caffeine (C3H10 N4O2) contains 6.02 x 10^23 molecules of
caffeine. If some energy drink contains 210. mg of caffeine, how many molecules of caffeine are present in the drink?
Answer:
6.52×10²⁰ molecules.
Explanation:
We'll begin by converting 210 mg of caffeine to grams (g). This can be obtained as follow:
Recall:
1 mg = 1×10¯³ g
Therefore,
210 mg = 210 mg / 1 mg × 1×10¯³ g
210 mg = 0.21 g
Therefore, 210 mg of caffeine is equivalent to 0.21 g of caffeine.
Finally, we shall determine the number of molecules in 0.21 g of caffeine as follow:
194 g of caffeine contains 602×10²³ molecules.
Therefore, 0.21 g of caffeine will contain = (0.21 × 602×10²³)/194 = 6.52×10²⁰ molecules.
Therefore 0.21 g contains 6.52×10²⁰ molecules.
Thus, we can say that 210 mg (i.e 0.21g) of caffeine contains 6.52×10²⁰ molecules.
What are non-examples of a nucleus
Answer:n a red blood cell, the control center is the nucleus. A mitochondria is not a nucleus. It is another organelle that produces energy for the cell.
Explanation:
What is the meaning of a positive or negative percent error?
Answer:
positive--real negative--not real
why is copper cobalt sulphide concentrates treated via roast rather than smelting
Explanation:
Cobalt extraction refers to the techniques used to extract cobalt from its ores and other compound ores. Several methods exist for the separation of cobalt from copper and nickel. They depend on the concentration of cobalt and the exact composition of the used ore.
Cobalt ore
Contents:
The ores are treated by a sulfatizing roast in a fluidized bed furnace to convert copper and cobalt sulfides into soluble sulfates and iron into insoluble hematite. The calcine is subsequently leached with sulfuric acid from the spent copper recovery electrolyte. Oxide concentrates are introduced at this leaching step to maintain the acid balance in the circuit. Iron and aluminum are removed from the leach solution by the addition of lime, and copper is electrowon on copper cathodes. A part of the spent electrolyte enters the cobalt recovery circuit and is purified by the removal of iron, copper, nickel, and zinc prior to the precipitation of cobalt as its hydroxide. This is accomplished by the addition of more lime to raise the pH until the remaining copper precipitates. This copper is sent back to the copper circuit. As more lime is then added, a copper-cobaltite precipitates and is fed back to the leaching process. Sodium hydrosulfide (NaHS) is added (along with some metallic cobalt as a catalyst) to precipitate nickel sulfide (NiS). Hydrogen sulfide (H2S) and sodium carbonate (Na2CO3) are then added to precipitate zinc sulfide (ZnS). Lime is then added to saturation to precipitate cobalt(II) hydroxide (Ca(OH)2). In the final stages, this cobalt hydroxide is redissolved and the metal is refined by electrolysis. The resulting cobalt cathodes are crushed and vacuum degassed to obtain a pure cobalt metal.
How many grams of NH4OH are present in 37.0 grams of 6.00 M NH4OH which has a density of 0.960 g/mL?
Answer:
The mass of NH₄OH present in the solution is 8.085 g
Explanation:
Given;
molarity of NH₄OH = 6 M
density of NH₄OH = 0.960 g/mL
mass of NH₄OH = 37.0 grams
volume of NH₄OH = mass /density
= 37/0.96
= 38.54 mL
molarity = moles of solute / Liters of solution
moles of solute = molarity x Liters of solution
moles of solute = 6 x 38.54 x 10⁻³
moles of solute = 0.231 moles
Reacting mass = number of moles x molecular mass
Molecular mass of NH₄OH = 35 g/mol
Reacting mass = 0.231 mol x 35 g/mol
Reacting mass = 8.085 g
Therefore, the mass of NH₄OH present in the solution is 8.085 g
A student measures the mass of an 11.2cm3 block of sugar to be 17.8 g. What is the density of the sugar?
Answer:
21 cm 3 that is the answer
How many significant figures does the number 0.00650
have?
Answer:
3
Explanation:
For decimals, you always start at the first non-zero number and count all the way to the end of the number. To count the number of significant figures this number has, you start at 6 and count every number after that for a total of 3.