Worksheet: Topic 6.1 Formulae

Q1. Chrome alum is a salt that contains two different cations and one anion.

The ions present in chrome alum are K⁺, Cr³⁺ and SO₄^2-.

What is the formula of the salt?

• A. KCrSO₄  

• B. KCr(SO₄)₂

• C. KCr(SO₄)₃

• D. K₂Cr(SO₄)₃

Q2. How many different elements are present in ammonium nitrate?

• A. 2

• B. 3

• C. 4

• D. 5

Q3. What is the formula of zinc oxide?

• A. Zn₂O

• B. ZnO

• C. Zn₂O₃

• D. ZnO₂

Q4. Which compound has an empirical formula that is different from its molecular formula?

• A. C₄H₁₀O

• B. H₂O

• C. NO₂

• D. H₂O₂

Q5. An ionic compound has the formula Al₂O₃. What are the charges on the ions?

• A. Al⁺ O^-

• B. Al²⁺ O^2-

• C. Al²⁺ O^3-

• D. Al³⁺ O^2-

6. Q6. What is the empirical formula of ethanoic acid?

• A. C₂H₄O₂

• B. CH₄O

• C. C₂H₃O

• D. CH₂O

Q7. The formula of ammonium metavanadate is NH₄VO₃.

It consists of NH₄ ions and VO₃ ions. What are the charges on these ions?

• A

• B

• C

• D

Q8. The atomic number of element X is 12.

What is the formula of the chloride of X?

• A. X₂Cl

• B. XCl

• C. XCl₂

• D. XCl₄

Q9. A covalent compound has the empirical formula CH₂O.

Which structure represents P?

• A

• B

• C

• D

Q10. In the ionic solid zinc phosphide, Zn₃P₂,

what is the formula of the phosphide ion?

• A. P³⁺

• B. P^3-

• C. P²⁺

• D. P^4-