Answer:
350J
Explanation:
Based on the first law of thermodynamics, which is the law of conservation of energy, energy can neither be created nor lost but can only be transformed. This implies that energy input of a system must equate the energy output as no energy can be lost.
In this case regarding an unlit match that contains 1000J of chemical energy. It burns to emit light energy and heat/thermal energy. If the amount of emitted thermal energy measured is 400J and the remaining/left over amount of chemical energy is 250J, this means that the missing amount of energy has been emitted as light energy.
To find the amount of light energy emitted, we say;
Amount of chemical energy - (thermal energy emitted + remaining chemical energy)
= 1000 - (400 + 250)
= 1000 - 650
= 350J
Hence, the amount of light energy emitted is 350J. This satisfies the law of conservation of energy because the output energy is equal to the total energy in the system.
Use the ruler to determine the length of this object. Record your answer to the nearest tenth. The object is ____ long.
Answer: 2.7 cm
Explanation: ~~~~~ there ya go
What is the maximum length of a polyethene chain with molar mass 10^6 and monomer length 2.5?
Answer:
L=7.0125*10^-5
Explanation:
LET
Length of polyethene chain= L
Molecular weight OF polyethene= MW
Molecular weight of monomer =mw
Monomer length= l
L=(MW/mw) *l
L= (28.05g/mol10^6gmol-1) * 2.5
L=70.125*10^-6
L=7.0125*10^-5
Hence, the length will be L=7.0125*10^-5 .
Is burning sugar a chemical or physical change? Please provide explanation
Answer:
It is a chemical change
Explanation:
the reason is because the will not be able to materialize back into it's original form.
For the following amino acid, the name, three-letter abbreviation, or one-letter abbreviation is given. Complete the missing information.Name: proline Three letter abbreviation:____________One letter abbreviation:________
Answer:
The correct answer is "Pro; P".
Explanation:
Amino acids are not only identified by its full name, there are three-letter and one-letter abbreviations for each amino acid that helps to annotate sequences and biological processes. In the case of proline, the three letter abbreviation is "Pro" and the one letter abbreviation is "P". Proline got its name for its cyclic structure, that resembles the structure of pyrrole.
Suppose now that you wanted to determine the density of a small crystal to confirm that it is graphite. From the literature, you know that graphite has a density of 2.25 g/cm^3. How would you prepare 20.0 mL of the liquid mixture having that density from pure samples of CHCl3 (d = 1.492 g/mL) and CHBr3 (d = 2.890 g/mL)? (Note: 1 mL = 1 cm^3.)
Answer:
The volume of first and second compound are 9.15 ml and 10.85 ml.
Explanation:
Given that,
Density of graphite = 2.25 g/cm³
Volume of mixture = 20.0 mL
Density of first compound = 1.492 g/ml
Density of second compound = 2.890 g/ml
Let the volume of first mixture = x
The volume of second mixture = (20-x)....(I)
We need to calculate the volume of first compound
Using formula of density of mixture
[tex]\rho=\dfrac{V_{1}\rho_{1}+V_{2}\rho_{2}}{V_{1}+V_{2}}[/tex]
Where, [tex]V_{1}[/tex] = volume of first compound
[tex]V_{2}[/tex] = volume of second compound
[tex]\rho_{1}[/tex] =density of first compound
[tex]\rho_{1}[/tex] = density of first compound
Put the volume into the formula
[tex]2.25=\dfrac{x\times1.492+(20-x)\times2.890}{x+20-x}[/tex]
[tex]45=1.492x+57.8-2.890x[/tex]
[tex]45-57.8=1.492x-2.890x[/tex]
[tex]12.8=1.398x[/tex]
[tex]x=\dfrac{12.8}{1.398}[/tex]
[tex]x=9.15\ ml[/tex]
We need to calculate the volume of second compound
Using equation (I)
[tex]V_{2}=20-x[/tex]
Put the value of x
[tex]V_{2}=20-9.15[/tex]
[tex]V_{2}=10.85\ ml[/tex]
Hence, The volume of first and second compound are 9.15 ml and 10.85 ml.
How does the government control scientific research?
O A. Scientists are dependent upon the government to set ethical
standards.
B. The government can take away money if a scientist is not
following ethical standards.
O C. The government determines which experiments are important.
D. Scientists can do only research that the government supports.
Answer: B) The government can take away money if a scientist is not following ethical standards
Explanation: hope this helped :)
The government control scientific research by taking away money if a scientist is not following ethical standards. Therefore, the correct option is option B.
While it is crucial to recognise that the government's role in scientific research is varied and extends beyond the control of ethical standards, funding agencies and institutions frequently require researchers to follow particular ethical norms and standards when conducting scientific investigations. Failure to adhere to these ethical norms may result in the loss or denial of research funding.
However, it is critical to recognise that the government's role in scientific research extends beyond simply enforcing ethical norms. Governments can also fund and support specific research areas or priorities, create regulations and guidelines for research practises, encourage researcher collaboration, provide infrastructure and resources, and establish policies that shape the overall direction and focus of scientific research.
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You are comparing a reaction that produces a chemical
change and one that produces a physical change. What
evidence could you use to determine which type of
change is occurring?
If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.
The stock solution is 100 μM the protocol calls for 10 mL solution of 80, 60, 40 and 20 μM. Compute the table.Target Concentration(μM) Volume of stock(mL) Volume of water(mL)20406080
Answer:
See the answer below
Explanation:
Using the dilution equation:
m1v1 = m2v2
m1 =100 μM, v1 = ?, v2 = 10 mL
In order to prepare 80 μM, then m2 = 80 μM
v1 = [tex]\frac{80*10}{100}[/tex] = 8 mL
In order to prepare 60 μM
v1 = [tex]\frac{60*10}{100}[/tex] = 6 mL
In order to prepare 40 μM
v1 = [tex]\frac{40*10}{100}[/tex] = 4 mL
In order to prepare 20 μM
v1 = [tex]\frac{20*10}{100}[/tex] = 2 mL
Since the final solution has to be up to the 10 mL mark, the complete table would be:
Target Concentration(μM) Volume of stock(mL) Volume of water(mL)
20 2 8
40 4 6
60 6 4
80 8 2
Which of the following is in intensive property a. mass b. magnetism c shape D. volume
Answer:
b. Magnetism (sorry im very late)
Explanation:
Intensive properties do not depend on size, no matter what it doesn't. For example, magnetism, density, melting and boiling points, and color. All of those support intensive property.
Intensive properties are physical properties that do not depend on the amount or size of the material being measured. In other words, they remain constant regardless of the quantity of the substance.
The correct answer is b. magnetism.
Out of the options provided:
a. mass is an extensive property because it depends on the amount of the substance. If you have more of a substance, you will have a greater mass.
b. magnetism is an intensive property because it remains the same regardless of the size or amount of the material with the magnetic property.
c. shape is not a standard property used to classify intensive or extensive properties. It is more of a description of the object's form.
d. volume is an extensive property because it depends on the size and amount of the substance. If you have more of a substance, you will have a larger volume.
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which of these substances are most likely crystalline solids?
Answer:
diamond
sugar
rubber
salt (NaCl)
wood
ice
flour
Answer:
diamond
sugar
salt
ice
Explanation:
In reading a line drawing, how do you know where atoms of these elements are in the structure if they are missing from the drawing?
Answer:
The atoms of an element are represented in a chemical line drawing with its chemical formula.
Explanation:
chemical structural drawing helps to represent the pattern for which an element is formed. Chemical elements are made up of atoms that represent their single state.
The line drawing is made up of lines (representing the chemical bond between atoms) and the atoms or various atoms that make up the element.
What is the density of a silver coin from the following data:
Mass of silver coin 6.581 g
Volume of coin and water 23.7 mL
Volume of water alone 23.1 mL
The answer is assumed to be in g/mL. Please type a numeric value only.
Answer:
you can use math wa, it helps
To prepare 100.0 mL of a 0.0525 M solution of NaCl in water, what mass of sodium chloride is needed? The
molar mass of NaCl is 58.44 g/mol.
Answer:
0.307 g
Explanation:
Step 1: Given data
Volume of solution: 100.0 mL
Molarity of the NaCl solution: 0.0525 M
Molar mass of NaCl: 58.44 g/mol
Step 2: Calculate the moles of NaCl required
The molarity is equal to the moles of solute (NaCl) divided by the liters of solution.
M = moles of NaCl / liters of solution
moles of NaCl = M × liters of solution
moles of NaCl = 0.0525 mol/L × 0.1000 L = 5.25 × 10⁻³ mol
Step 3: Calculate the mass corresponding to 5.25 × 10⁻³ moles of NaCl
5.25 × 10⁻³ mol × 58.44 g/mol = 0.307 g
A car drives on a road at a constant speed of 50 miles/hour.
The forward force of the car is ________________
the opposing friction and air
resistance forces.
The forward force of the car and the opposing friction and air resistance forces are ____________
( !!
Answer:
It will take the police car 3.5 hours to travel a distance of 175 miles traveling at a rate of 50 miles/hour.
Explanation:
What is a factual statement about how nature behaves or functions?
a hypothesis
O a law
O a theory
an experiment
Answer:its a law
Explanation:
I passed that quiz 100%, my answer for that question was law
so its law
Ocean water becomes colder; the density of ocean water increases or decreases?
Answer:
.............increases
An atom's Lewis dot structure has four dots. Which of the following elements could it be, and why?
Answer: Carbon, because it is in group 14 and has four valence electrons
Explanation: Just did this quiz
Answer:carbon
Explanation:
Draw structures for compounds that meet the following descriptions in proton NMR:a) C2H6O; one singletb) C3H7Cl; one doublet and one septetc) C4H8Cl2O; two tripletsd) C4H8O2; one singlet, one triplet, and one quartet
Answer:
The structures are shown in the attachments.
Explanation:
Please see the attachments below for the structures.
Explanation:
For the structure in (a)There is only one environment denoted as 'a'.
Using the (n+1) rule to determine the multiplicity, m
where is the number of neighboring Hydrogen, then
Since, n = 0, then
m = 0 + 1 = 1 (which means singlet)
Hence, one singlet
For the structure in (b)There are two environments denoted as 'a' and 'b'
For 'a' ; n = 6
Hence, m = n + 1
m = 6 + 1 = 7 (this means septet)
For 'b'; n = 1
then, m = n + 1
m = 1 + 1 = 2 (this means doublet)
Hence, one septet, one doublet
For the structure in (c)There are two environments denoted as 'a' and 'b'
For 'a' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
For 'b' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
Hence, two triplets
For the structure in (d)There are three environments denoted as 'a', 'b', and 'c'
For 'a' ; n = 0
Hence, m = n + 1
m = 0 + 1 = 1 (this means singlet)
For 'b' ; n = 3
then, m = n + 1
m = 3 + 1 = 4 (this means quartet)
For 'c' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
Hence, one singlet, one triplet, and one quartet
What is the A# of fluoride-19?
Answer:
atomic number of fluorine
is 9
Can someone please help me with these questions!!!!!!
Answer:
1. A. 10°C
2. A. Boiling point
3. A. Less than liquids.
Explanation:
Sort the following analytical techniques as either classical methods or instrumental methods.
a) surface analysis
b) precipitation titration
c) gravimetric analysis
d) high performance liquid chromatography
e) potentiometry
f) atmoic spectroscopy
Answer:
Instrumental methods
surface analysis
high performance liquid chromatography
atomic spectroscopy
potentiometry
Classical methods
precipitation titration
gravimetric analysis
Explanation:
Instrumental methods of analysis are those analytical methods in which the responsibility of detection has been removed from human beings and placed on automated instruments while classical methods are those analytical methods in which the responsibility of detection remains the responsibility of human beings.
Many instrumental methods such as HPLC rely on computer screens as readout devices.
How is it possible for water to be polar but uncharged?
hey can anyone help me with organic chemestry?
Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.
Answer: 45.983 g CBr₄
Explanation:
To convert from moles to grams, you know that we will need molar mass and Avogadro's number.
Avogadro's number: 6.022×10²³ molecules/mol
Molar mass: 331.627 grams/mol
Now that we have what we need, you can use these to solve for grams. [tex]8.35*10^2^2molecules CBr_{4} *\frac{1mol}{6.022*10^2^3molecules} *\frac{331.627 g}{1 mol} =45.983 g[/tex]
Our final answer is 45.983 g CBr₄.
Can someone please help me w these chemistry conversion? 1. The density of Mercury is 13.6 g/mL. What is the volume of mercury, in quarts has a mass of 95.0 ounces? 2. Tetrachloroethylene, also called PERC, has a density of 1.62 g/mL. It was formerly used as a dry cleaning solvent. What is the mass in pounds of PERC contained in a 55.0 gallon drum? 3. Osmium is the most dense element having a density of 22.5 g/cm^3 Calculate the density of osmium in kg/m^3. 4. The density of Iron is 7.50 g/cm^3. What is the mass, in pounds, of a cube of iron that measures 5.00 cm on a side? 5. Lead has a density of 10.5 g/cm^3. What is the diameter of a lead ball that has a mass of 500.0 g? Report answer in cm.
Answer:
1. 0.209quart
2. 743.6pounds
3. 22500kg/m^3
4. 2.07pounds
5. 4.50cm
Explanation:
Note that, these questions are related to density which can be calculated using the formula:
Density (p) = Mass (m) / Volume (v)
However, the units are different for each questions, hence, must be made the same
1. 1 ounce = 28.35 grams
95 ounces will be 95 × 28.35 = 2693.2g
Volume = mass/density
Volume of Mercury= 2693.2/13.6
Volume= 198ml
1 ml = 0.00106quart
198ml = 198 × 0.00106 = 0.209quart
2. 1 gallon = 3785.4ml
55 gallons = 55× 3785.4 = 208197ml
Mass = density × volume
Mass = 1.62 × 208197
Mass = 337,279.14g
1 pounds = 453.592 g
337279.14 g = 337279.14/453.592
Mass = 743.6pounds
3. 1g/cm^3 = 1000kg/m^3
Hence, a density of 22.5g/cm^3 will be 22.5 × 1000 = 22500kg/m^3
4. Volume of a cube of side 5cm each will be 5×5×5 = 125cm^3
Density = 7.50g/cm^3
Mass = Density×volume
Mass in grams = 7.50 × 125
Mass = 937.5grams
1 pound = 453.592 g
Therefore, 937.5g will be 937.5/453.592 = 2.07pounds.
5. Volume = Mass / density
Volume = 500/10.5
Volume = 47.62cm^3
Since a ball is spherical in shape, volume of a sphere (V) = 4/3πr^3
To find radius, we say;
47.62 = 1.33 × 3.142 × r^3
47.62 = 4.179 × r^3
r^3 = 47.62/4.179
r^3 = 11.395
r = 3√11.395
r = 2.25cm
To get diameter (d), we multiply the radius (r) by 2,
d = 2 × 2.25
d= 4.50cm
Question 13 of 16
The mass of a piece of metal is 25.4253 grams. When the piece of
metal was dropped into a graduated cylinder that had an initial water
volume of 6.85 cm, the total volume was 9.84 cm? What is the
density of the piece of metal in g/cm??
Answer:
[tex]\rho =8.50g/cm^3[/tex]
Explanation:
Hello,
In this case, due to the volume difference caused by the addition of the metal, one could notice that the volume of the metal is:
[tex]V_{metal}=9.84cm^3-6.85cm^3=2.99cm^3[/tex]
In such a way, given the mathematical definition of density, it turns out:
[tex]\rho =\frac{m}{V}=\frac{25.4253g}{2.99cm^3}\\\\\rho =8.50g/cm^3[/tex]
Regards.
How would replacing many amino groups with carboxyl groups change the properties of the compound?
Answer:
This replacements will make the compound less basic and more acidic
Explanation:
Replacing amino groups (-NH₂) which act as bases [because of there ability to accept hydrogen ion (H⁺)] with carboxyl group (-COOH) which acts as acid [because of it's ability to donate hydrogen ion (H⁺)] in a compound changes the property of the compound to be less basic and more acidic.
Enter a balanced equation for the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Answer:
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
Explanation:
Let's consider the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Pb(NO₂)₂(aq) + LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
This is a double displacement reaction. We will start balancing Cl by multiplying LiCl by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
Now, we have to balance Li by multiplying LiNO₂ by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
The equation is now balanced.
The balanced chemical reaction equation required is; Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
In order to write a balanced chemical reaction equation, we must write down the symbols of the compounds involved as follows;
lead (II) nitrite - Pb(NO2)2
lithium chloride - LiCl
lead (II) chloride - PbCl2
lithium nitrite - LiNO2
Recall that the principle of writing a balanced chemical reaction equation is that the number of atoms of each element on both sides of the reaction equation must be the same. The required balanced chemical reaction equation is;
Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
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The diameter of an atom is approximately 1 * 10 ^ - 10 * m . What is the diameter in decimeters?
Answer:
[tex]d=1x10^{-9}dm[/tex]
Explanation:
Hello,
In this case, considering that 1 m equals 10 dm, the required diameter of the atom in decimetres is:
[tex]d=1x10^{-10}m*\frac{10dm}{1m} \\\\d=1x10^{-9}dm[/tex]
Best regards.
convert 6.8 × 10^2 to standard notation.
Answer:
680
Explanation:
Move the decimal 2 to the right.
When a number is written using only the digits of the number, that is considered standard notation. 6.8 × 10² is converted into standard notation by shifting two decimal to the right side, then it became 680.
What is standard notation ?A form of writing a certain number, an equation, or an expression in a way that adheres to set norms is known as a standard notation. For instance, 4,500,000,000 years is how 4.5 billion years is written.
When a number is written using only the digits of the number, that is considered standard notation. Since words are not used in conventional number notation, this is the way that numbers are typically written.
The stages to writing a number in its standard form are as follows: Write the first digit of the supplied number in step one. Step 2: After the first number, add the decimal point. Step 3: Next, count how many digits there are in the supplied number after the first one and express that number as a power of 10.
Thus, the standard notation is 680.
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