Free Printable Writing Empirical and Molecular Formulas

1.

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

a)

NaPO2

b)

Na2PO3

c)

Na3PO4

d)

NaPO4

2.

What is the molecular formula if the empirical formula is C₂H₅ and the molecular molar mass is 58.14 g/mol?

a)

C₂H₅

b)

C₄H₁₀

c)

C₁H_2.5

d)

C₄H₈

3.

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

a)

Mg₄N₃

b)

MgN₂

c)

Mg₃N₂

d)

MgN

4.

What is the molecular formula for a compound with the empirical formula: K₂SO₄and a molecular mass of 696g.

a)

K₂SO₄

b)

K₈SO₁₆

c)

K₈S₄O₈

d)

K₈S₄O₁₆

5.

A compound has an empirical formula of $NO_2$ and a molecular weight of 92 g/mol. What is its molecular formula?

a)

$NO_2$

b)

$N_2O_4$

c)

$N_3O_6$

d)

$N_4O_8$

6.

Which of the following is a correct example of an empirical formula?

a)

$C_6H_{12}O_6$

b)

$C_2H_4O_2$

c)

$CH_2O$

d)

$C_3H_6O_3$

7.

If the empirical formula of a compound is $CH_2$ and its molecular weight is 56 g/mol, what is the molecular formula?

a)

$C_2H_4$

b)

$C_3H_6$

c)

$C_4H_8$

d)

$C_5H_{10}$

8.

If a compound has an empirical formula of $C_2H_5$ and a molecular weight of 58 g/mol, what is its molecular formula?

a)

$C_2H_5$

b)

$C_3H_8$

c)

$C_4H_{10}$

d)

$C_5H_{12}$

9.

A formula with the lowest whole # ratio of elements in a compound is called

a)

Molecular Formula

b)

Chemical Formula

c)

Empirical Formula

d)

Distance Formula

10.

What is the empirical formula for N₂S₃?

a)

NS

b)

N₃S₂

c)

N₂S₃

d)

N₁S_1.5

11.

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

a)

ionic formula

b)

covalent formula

c)

empirical formula

d)

molecular formula

12.

How many Carbons "C" are in C₁₈H₃₄O₃

a)

18

b)

34

c)

3

d)

37

13.

Which pair has the same empirical formula?

a)

NaCrO₄ and Na₂Cr₂O₇

b)

C₂H₄O₂ and C₆H₁₂O₆

c)

C₃H₆O₃and C₂H₆O₂

d)

CH₄ and C₂H₆

14.

Which one is an empirical formula?

a)

H₂O₂

b)

C₂H₆O₁₂

c)

CaCl₂

d)

N₂O₈

15.

Which of these is NOT an empirical formula?

a)

CH2

b)

C2H5

c)

C6H4

d)

C3H7

e)

C5H17

16.

What is the empirical formula of K₂SO₄?

a)

K₂SO₄

b)

KSO₂

c)

K₂SO₂

d)

KSO₈

17.

A compound is composed of 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula?

a)

$CH_2O$

b)

$C_2H_4O_2$

c)

$C_3H_6O_3$

d)

$C_6H_{12}O_6$

18.

If the empirical formula of a compound is $CH_2O$ and its molecular weight is 180 g/mol, what is the molecular formula?

a)

$C_6H_{12}O_6$

b)

$C_2H_4O_2$

c)

$C_3H_6O_3$

d)

$C_4H_8O_4$

19.

A compound has an empirical formula of $NH_2$ and a molecular weight of 32 g/mol. What is its molecular formula?

a)

$N_2H_4$

b)

$NH_2$

c)

$N_3H_6$

d)

$N_4H_8$

20.

Which of the following is a correct example of a molecular formula?

a)

$C_6H_{12}O_6$

b)

$CH_2O$

c)

$C_2H_4O_2$

d)

$C_3H_6O_3$

21.

A compound consists of 85.7% carbon and 14.3% hydrogen by mass. What is the empirical formula?

a)

$CH_2$

b)

$C_2H_4$

c)

$C_3H_6$

d)

$C_4H_8$

22.

What is the empirical formula for a compound with the molecular formula $C_4H_8$ ?

a)

$CH_2$

b)

$C_2H_4$

c)

$C_3H_6$

d)

$C_4H_8$

23.

A compound has an empirical formula of $C_2H_5$ and a molecular weight of 58 g/mol. What is its molecular formula?

a)

$C_4H_{10}$

b)

$C_2H_5$

c)

$C_3H_8$

d)

$C_5H_{12}$

24.

Which of the following is NOT an empirical formula?

a)

$C_6H_6$

b)

$CH$

c)

$C_2H_4$

d)

$C_3H_6$

25.

A compound has an empirical formula of $C_3H_4$ and a molecular weight of 80 g/mol. What is its molecular formula?

a)

$C_6H_8$

b)

$C_3H_4$

c)

$C_9H_{12}$

d)

$C_{12}H_{16}$

Writing Empirical and Molecular Formulas

Total questions: 25

Worksheet time: 25mins

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