Chapter 1 Moles and Stoichiometry Questions

How many g are there in 7.3 moles of boron?

• 0.68

• 70.0

• 1.48

• 78.8

How many moles of chlorine are there in 213g of Cl₂?

• 3.0

• 6.0

• 0.17

• 0.33

How many g are there in 2.5 moles of oxygen, O₂?

• 40.0

• 80.0

• 6.4

• 4.0

It was found that 0.015 moles of atoms of an element had a mass of 2.88g. What is the relative atomic mass of the element?

• 200

• 192

• 432

• 450

From the previous answer, then the element's identity is

• Ir

• Os

• Hg

• Re

Given the following relative atomic masses: H = 1, O = 16 and Al = 27, calculate the relative formula mass of aluminium hydroxide

• 78

• 132

• 46

• 44

Given the following relative atomic masses: H = 1, N = 14, O = 16 and S = 32; calculate the relative formula mass of ammonium sulphate

• 216

• 63

• 100

• 132

Given the atomic masses: Cu = 64, S = 32 and O = 16; calculate the % by mass of sulphur in copper(II) sulphate

• 16.7

• 32.0

• 20.0

• 16.0

If 40g of calcium combines with 160g of bromine, what is the formula of calcium bromide? (Relative atomic masses: Ca = 40 and Br = 80)

• CaBr₃

• CaBr₂

• Ca₂Br

• CaBr

In an experiment, excess chlorine was passed over 27g of heated aluminium metal until all the metal had reacted. If 133.5g of white aluminium chloride was formed work out the formula of aluminium chloride. (Relative atomic masses: Al = 27 and Cl = 35.5)

• AlCl₂

• Al₃Cl

• AlCl₄

• AlCl₃