Free Printable Empirical and Molecular Formulas

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Empirical and Molecular Formulas

Total questions: 45

Worksheet time: 1hrs 29mins

Name

Class

Date

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

CH₂O

C₂H₄O₂

C₄H₈O₄

C₆H₁₂O₆

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

K₂SO₄

K₈SO₁₆

K₈S₄O₈

K₈S₄O₁₆

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

C₂H₃O₂

CH₂O

C₂H₄O₂

C₃H₈O₃

Empirical Formula = CF₂

Molecular formula mass = 192

Molecular Formula = ?

C₄F₈

C₄F

CF₈

C₂F₄

Phenyl magnesium bromide is used as a reagent in organic synthesis. Determine its molecular formula if its molar mass is 181.31 g/mol and it contains 39.75% C, 2.78% H, 13.41% Mg, and 44.07% Br (these are in the correct order).

C₁₂H₁₀Mg₂Br₂

CHMgBr

C₆H₅MgBr

C₃H_2.5MgBr

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

C₂H₅

C₄H₁₀

C₁H_2.5

C₄H₈

What is the molecular formula of a compound with an empirical formula of C₂OH₄ and a molar mass of 88 grams per mole?

C₂O₄H₈

C₈O₂H₄

C₄O₂H₈

C₄O₈H₂

What is the molecular formula for a compound with the empirical formula: CaCl₂and a molecular mass of 330g.

Ca₂Cl₄

Ca₃Cl₆

Ca₃Cl₉

Ca₃Cl₅

What is the molecular formula for a compound with the empirical formula: CaCl₂and a molecular mass of 220g.

Ca₂Cl₄

Ca₃Cl₆

Ca₃Cl₉

Ca₃Cl₅

10.

The empirical formula of a substance is CH₂O. The molar mass is 180g/mol. What is the molecular formula?

CH₂O

C₃H₆O₃

C₆H₁₂O₆

C₁₂H₆O₁₂

11.

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

Molecular Formula

Chemical Formula

Empirical Formula

Distance Formula

12.

What is the empirical formula for C₄H₆?

CH₃

C₂H₃

C₄H₆

13.

What is the empirical formula for N₂S₃?

N₃S₂

N₂S₃

N₁S_1.5

14.

Si₂F₆

Choose the correct empirical formula...

SiF

Si₂F₆

SiF₃

Si₆F₂

15.

What is the empirical formula for:

C₂H₆O₄

CHO

CH₂O

CO₂

CH₃O₂

16.

Which pair has the same empirical formula?

NaCrO₄ and Na₂Cr₂O₇

C₂H₄O₂ and C₆H₁₂O₆

C₃H₆O₃and C₂H₆O₂

CH₄ and C₂H₆

17.

What is the empirical formula of the following molecular formula: C₃H₆

C₃H₆

CH₂

C₂H₄

CH₃

18.

Which one is an empirical (cannot be simplified further)

H₂O₂

C₂H₆O₁₂

CaCl₂

N₂O₈

19.

What is the empirical formula for the following molecular formula: C₆H₁₄

C₆H₁₄

C₃H₇

CH₂

CH₃

20.

What is the empirical formula for the following:
Pb₅Cr₅O₂₀

Pb₂Cr₂O₁₀

PbCr₂O₇

Pb₉Cr₄O₂

PbCrO₄

21.

What is the empirical formula for hydrogen peroxide in the picture?

H₂O₂

H₂O

HO₂

22.

Which is not considered an empirical formula?

P₄H₁₀

P₂H₅

H₂CO₃

NaCl

23.

Which is not considered an empirical formula?

SiO₂

CCl₄

CH₂O

C₄H₁₀

24.

Which of these is considered to be an empirical formula

CO₂

C₃H₆

C₂H₆

C₂O₄

25.

Which of these formulas is an empirical formula?

N₂O₄

N₂O

N₂O₆

N₄O₄

26.

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

Mg₄N₃

MgN₂

Mg₃N₂

MgN

27.

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

SO2

SO3

SO4

28.

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

NaPO2

Na2PO3

Na3PO4

NaPO4

29.

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

C₂H₃O₂

CH₂O

C₂H₄O₂

C₃H₈O₃

30.

Whats the empirical formula of a molecule containing 18.7% of Lithium, 16.3% of Carbon and 65.0% of oxygen?

CO₂Li₃

Li₂CO₃

Li₃CO₂

LiCO₅

31.

What is the percent by mass of oxygen in MgO?

20%

40%

50%

60%

32.

What is the percent by mass of sodium in NaCl?

39%

61%

35%

65%

33.

What is the percent by mass of fluorine in CaF₂(gram-formula mass = 78 g/mol)?

24%

49%

51%

65%

34.

In which compound is the percent composition by mass of Cl equal to 42%?

HClO (gram formula mass = 52 g/mol)

HClO₂ (gram formula mass = 68 g/mol)

HClO₃ (gram formula mass = 84 g/mol)

HClO₄ (gram formula mass = 100 g/mol)

35.

In which compound is the percent composition by mass of Cl equal to 42%?

HClO (gram formula mass = 52 g/mol)

HClO₂ (gram formula mass = 68 g/mol)

HClO₃ (gram formula mass = 84 g/mol)

HClO₄ (gram formula mass = 100 g/mol)

36.

2.40 g of an explosive, J, contains 0.473 g of nitrogen. J also contains 33.8% carbon and 1.41% hydrogen by mass. The remainder of J is oxygen.

What is the empirical formula of J?

C₄HNO₂

CH₂N₂O

C₂HNO₂

CHNO

37.

C₁₂H₁₀Mg₂Br₂

CHMgBr

C₆H₅MgBr

C₃H_2.5MgBr

38.

An unknown compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. It has a molecular mass of 60.0 g/mol. Calculate its molecular formula.

(a)

39.

A hydrocarbon contains 85.7% carbon with a molecular mass of 84.0 g/mol. Calculate its molecular formula.

(a)

40.

A piece of iron ore contains 72.3% iron and 27.7% oxygen with a molecular mass of 231.4 g/mol. Calculate its molecular formula.

(a)

41.

A compound contains 87.4% nitrogen. The remainder is hydrogen. If the molecular mass is 32 g/mol, what is its molecular formula?

(a)

42.

A compound with a molar mass of 74 g/mol contains 64.8% carbon and 13.5% hydrogen. When it was burned it produced carbon dioxide and water. Calculate its molecular formula.

(a)

43.

A compound contains 24.8% carbon, 2.0% hydrogen and 73.2% chlorine. It has a molar mass of 96 g/mol. Calculate its molecular formula.

(a)

44.

An oxide of nitrogen contains 46.7% nitrogen and has a molecular mass of 60 g/mol. What's its molecular formula?

(a)

45.

A gas sample contained the elements carbon, hydrogen, oxygen, phosphorus and fluorine in the respective quantities: 39.10%, 7.67%, 26.11%, 16.82% and 10.30%. It has a molecular mass of 184 g/mol. What is the molecular formula for this compound?

(a)

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Empirical and Molecular Formulas

Total questions: 45

Worksheet time: 1hrs 29mins

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