Chemistry 5070 · O Level · The mole and the Avogadro constant

The mole and the Avogadro constant — practice question

Acid U is a compound made up of carbon, hydrogen and oxygen.
(a)[3]

A 6.30 g sample of U contains 1.68 g of carbon and 0.14 g of hydrogen. Calculate the empirical formula of U.

(b)[3]

A 0.086 g sample of U is completely neutralised by $12.7\,\text{cm}^3$ of $0.150\,\text{mol dm}^{-3}$ KOH. One mole of U reacts with two moles of KOH. Calculate the relative formula mass of U.

(c)[1]

State the molecular formula of U.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Calculate the moles / mole ratio

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