All categories

3 years ago

Which of the following is a chemical change?

Chemistry

2 answers:

Basile [38]3 years ago

8 0

I think that it’s A i have done a test on this before so I think it’s A

garik1379 [7]3 years ago

7 0

the answer is B not A

let me explain why see a says water vapor in the air turns to liquid water in the form of rain see that is a physical change not a chemical change it is B because it is undergoing a chemical change by the uv rays for that reason it is not D because that is just releasing sulfur dioxide in the air that is not a chemical change nor a physical change so then i leaves us with C so C is wrong because it just being suspended in the air not physical or chemical change

can i also have brainlyest i never had it before

You might be interested in

A nitrogen oxide, containing 53.85% N, acts as a vasodilator, lowering blood pressure in the human body. What is its empirical f

jenyasd209 [6]

The empirical formula of the nitrogen oxide that acts as a vasodilator and lowers human blood pressure is $N_4O_3$ . Empirical formula is the smallest whole number ratios of elements in a compound.

FURTHER EXPLANATION

To get the empirical formula from mass percent data, the following steps are followed:

1. Get the mass percent data for all the elements that make up the compound.

2. Assume that there is 100 grams of sample compound. Determine the equivalent masses of each element using the mass percent given.

3. Convert the mass of each element to number of moles.

4. Divide each calculated mole by the smallest mole value.

5. The quotient will be the subscript of the element in the compound. If a decimal is obtained, round off the answers to the nearest whole number. Some exceptions to this are the following decimals: x.25, x.33, x.50, and x.75. When these decimals are obtained, all the subscripts are multiplied by a number that will result in a whole number.

Applying the steps to the problem,

STEP 1: Get the mass percent.

Mass % of N = 53.85

Mass % of O = (100 - 53.85) = 46.15

STEP 2: Assume that 100 g sample is used and convert the mass % to mass in grams.

mass of N = 53.85% x 100 g = 53.85 g

mass of O= 46.15% x 100 g = 46.15 g

STEP 3: Convert mass to moles by dividing the given mass by the formula mass.

$moles \ of \ N \ = 53.85 \ g (\frac{1 \ mol}{14 \ g}) = 3.85 \\\\moles \ of \ O \ = 46.26 \ g \ (\frac{1 \ mol}{16 \ g}) \ = 2.89$

The moles may be written as the temporary subscripts of the elements in the compound as follows:

$N_{3.85}O_{2.89}$

STEP 4: Divide the moles by the smallest mole value.

$N_{3.85}O_{2.89}\\N_{ \frac{3.85}{2.89}} \ O _{ \frac{2.89}{2.89}} \\ N_{1.33}O_{1}\\$

<u>STEP 5:</u> Multiply the subscripts by a number that would give the smallest whole number ratio.

Since the decimal is 1.33 it cannot be rounded off to 1. It should be multiplied by 3 to get the smallest whole number.

NOTE: All subscripts must be multiplied by the same factor, 3.

$N_{1.33}O_{1}\\3(N_{1.33}O_{1})\\\boxed {N_{4}O_{3}}$

To check if the empirical formula is correct, calculate the mass % of each element based on the formula and compare with the given in the problem.

$mass \ \%\ = (\frac{mass \ of \ element}{mass \ of \ compound}) x 100\\\\mass \ \% \ of \ N = \ \frac{(4)(14)}{(4)(14) \ + \ (3)(16)}$

$mass \ \% \ of \ N \ = 53.85%\\mass \ \% \ of \ O \ = (\frac{(3)(16)}{(4)(14)+(3)(16)}) \ 100\\mass \ \% \ of \ O \ = 46.15%$

Since the values are the same from the given, the answer is correct.

LEARN MORE

Writing Chemical Formula brainly.com/question/4697698
Naming Compounds brainly.com/question/8968140
Mole Conversion brainly.com/question/12979299

Keywords: empirical formula, compounds

6 0

3 years ago

Read 2 more answers

Which of the following determines the identity of an element?

nalin [4]

B mass number because it can be observed with out changing the element

4 0

3 years ago

A student uses red litmus paper to test the pH value of different solutions. Which would result in a color change of the litmus

OverLord2011 [107]

The answer is all of the above but fertilizer

5 0

4 years ago

Read 2 more answers

The compound that cannot have a branched structure is select one:

yanalaym [24]

C3H8

There is only one isomer of propane:

H H H
HC-C-CH
H.H H

It’s easier to see I’m a bond line formula; however, You can see that trying to take a methyl group off and move it results in the same structure.

4 0

4 years ago

What type of elements make up most of the periodic table

nignag [31]

Basic elements, and components make up most of the periodic table of elements

4 0

4 years ago

Read 2 more answers