Mole Concept

Which of the following quantities of acid can exactly neutralize 40 cm³ of 2.0 mol dm^-3 sodium hydroxide?

• 10 cm³ of 2.0 mol dm^-3 hydrochloric acid

• 10 cm³ of 4.0 mol dm^-3 sulphuric acid

• 20 cm³ of 4.0 mol dm^-3 nitric acid

Which of the following ions requires the LARGEST number of moles of electrons to liberate one mole of it?

• Al³⁺

• Cl^-

• Cu²⁺

• O^2-

Which of the following mixtures can be referred to as a standard solution?

• Iodine in 50 cm³ of ethanol

• Sodium chloride in 50 cm³ of water

• 30 g of sodium chloride in water

• 30 g of iodine in 50 cm³ of ethanol

Which of the following compounds has the GREATEST percentage by mass of carbon present in one mole? ( M_r = relative molecular mass; relative atomic mass: H =1; C = 12; O = 16)

• C₂H₄O₂ (M_r = 60)

• C₃H₈O (M_r = 60)

• C₂H₆O (M_r = 46)

• C₆H₁₂O₆( M_r = 180)

The mass of '1 mole of atoms of an element' refers to the quantity of

• 1 atom of the element

• an element which contains 6.0 x 10²³ atoms

• an element which occupies 24.0 dm³ at STP

• an element which combines completely with 12 g of carbon-12

The mass concentration of a potassium chloride solution is 60 g dm^-3. What is the mass of potassium chloride in 25 cm³ of this solution?

• 0.0015 g

• 0.15 g

• 1.5 g

• 15.0 g

Select the acids which which would require MORE than one mole of NaOH_(aq) for complete neutralization?

• H₂SO₄

• CH₃COOH

• (COOH)₂

Sodium reacts with water according to the equation

2Na_(s) + 2H₂O_(l) -> 2NaOH_(aq) + H_2(g)

(Molar volume of gas = 24 litres at rtp)

The number of litres of hydrogen (at rtp) liberated when 0.1 mole of sodium reacts with excess water is

• 1.2

• 2.4

• 12.0

• 24.0

Which of the following aqueous solutions contains 1 mole of hydrogen ions?

• 2 dm³ of 0.5 mol dm^-3 HCl

• 2 dm³ of 0.5 mol dm^-3 H₂SO₄

• 1 dm³ of 1.0 mol dm^-3 H₂SO₄

• 1 dm³ of 1.0 mol dm^-3 CH₃COOH

Which two of the following represent equal quantities of atoms?

(Relative mass number: C = 12; S=32; Mg =24; Na=23)

• 12 g of carbon

• 16 g of sulfur

• 23 g of sodium

• 12 g of magnesium