6.5 Concentration of Aqueous Solution 6.6 Standard Solution

What is the mass of sodium hydroxide present in 100 cm3 of 2.0 mol/dm3 sodium hydroxide solution? [Relative atomic mass: H = 1, O=16, Na = 23]

• 2.0 g

• 4.0 g

• 8.0 g

• 10.0 g

What is the mass of potassium hydroxide needed to prepare 250 cm3 of 0.5 mol/dm3 standard solution? [Relative atomic mass: H = 1, O =16, K=39]

• 7 g

• 14 g

• 21 g

• 28 g

What is the mass of sodium nitrate, NaNO3 needed to prepare 500 cm3 of 0.1 mol/dm3 sodium nitrate solution? [Relative atomic mass: N=14, O=16, Na=23]

• 2.125 g

• 4.25 g

• 8.50 g

• 17.0 g

Excess zinc is reacted with 100 cm3 of 2 mol/dm3 hydrochloric acid. What is the volume of hydrogen gas formed at standard temperature and pressure, STP? [Molar volume of gas is 22.4 dm3/mol at STP]

• 1.12 dm3

• 2.24 dm3

• 3.36 dm3

• 4.48 dm3

When 14 g of KOH is dissolved in V cm3 of water, a solution with a concentration of 0.5 mol/dm3 is obtained. Determine the value of V. [Relative atomic mass: H=1, O=16, K=39]

• 100 cm3

• 200 cm3

• 250 cm3

• 500 cm3

Calculate the volume of sulphuric acid, H2SO4 of 2.0 mol/dm3 needed for dilution to produce 200 cm3 of 1.0 mol/dm3 of sulphuric acid.

• 50 cm3

• 100 cm3

• 200 cm3

• 400 cm3

100 cm3 of distilled water is added to 400 cm3 of 2.0 mol/dm3 hydrochloric acid. What is the molarity of the solution formed?

• 1.6 mol/dm3

• 1.8 mol/dm3

• 2.0 mol/dm3

• 2.5 mol/dm3

Which of the following contains most numbers of hydrogen ions?

• 400 cm3 of 1.0 mol/dm3 of sulphuric acid

• 700 cm3 of 1.0 mol/dm3 of ethanoic acid

• 600 cm3 of 1.0 mol/dm3 of hydrochloric acid

• 400 cm3 of sodium hydroxide 1.0 mol/dm3

A salt X solution has a concentration of 30.25 g/dm3. Its molarity is 0.5 mol/dm3. Calculate the relative formula mass for salt X.

• 0.0165

• 15.125

• 60.5

• 141

Molarity of a bottle of potassium hydroxide is 1.5 mol/dm3. What is the concentration in g/dm3? [Relative atomic mass: K=39, H=1, O=16]

• 25

• 50

• 84

• 90