Mole Concept Quiz

What is the number of moles of oxygen atoms in 1 mole of anhydrous calcium ethanoate, Ca(CH3COO)2?

• 2

• 4

• 32

• 64

14 g of nitrogen gas consists of the same number of molecules as

• 1 mole of carbon dioxide

• 8 g of oxygen gas

• 14 g of carbon monoxide

• 2 g of hydrogen gas

A metal M forms a hydroxide M(OH)3. The relative molecular mass of this hydroxide is 78. What is the relative atomic mass of the metal M?

• 30

• 27

• 59

• 75

A compound has a composition of 50 % sulfur and 50 % oxygen by mass. What is the empirical formula of the compound?

• SO

• S2O

• SO2

• S2O3

When 5 cm3 of a gaseous hydrocarbon was mixed with excess oxygen, O2 and the mixture exploded, 30 cm3 of carbon dioxide, CO2 and 15 cm3 of steam, H2O were produced. All volumes of gases were measured at the same temperature and pressure. The formula of the hydrocarbon could be

• CH4

• C2H4

• C3H6

• C6H6

The symbol for Avogadro's number is L. What is the mass, in grams, of one molecule of oxygen, O2?

• L ÷ 16 g

• 16 ÷ L g

• 32 ÷ L g

• L ÷ 32 g

Which one of the following statements about one mole of gas is false?

• It contains the Avogadro's number of particles.

• It has the same mass as one mole of any other gas.

• It occupies 24 dm3 at room temperature and pressure.

• It has a mass equal to its relative molecular mass in grams.

256 g of sulfur dioxide reacts with 60 dm3 of excess oxygen to produce sulfur trioxide according to the following equation: 2SO2 (g) + O2 (g) → 2SO3 (g) What is the total volume of gases left after the reaction assuming that the above reaction goes to completion? All volumes of gases were measured at the same temperature and pressure.

• 12 dm3

• 48 dm3

• 96 dm3

• 108 dm3

Phosphine (PH3) and hydrogen iodide (HI) react together when mixed at room temperature according to the following equation: PH3 (g) + HI (g) → PH4I (s) When 100 cm3 of phosphine is added to 80 cm3 of hydrogen iodide at room temperature and pressure

• one mole of product is obtained

• the volume after mixing is 180 cm3 at r.t.p.

• the volume after mixing is 100 cm3 at r.t.p.

• the volume after mixing is 20 cm3 at r.t.p.

A car burns octane vapour (C8H18) with oxygen gas at the same temperature and pressure. The products are carbon dioxide (CO2) and steam (H2O). What is the ratio of the volume of the gaseous products to the volume of the gaseous reactants?

• 17 : 2

• 34 : 25

• 34 : 27

• 17 : 25