IB Chemistry stoichiometry open-ended questions past papers base

The relative molecular mass of Aluminium Chloride is 267 and its composition by mass is 20.3% Al and 79.7% Chlorine. Determine the empirical and molecular formulas of Aluminium Chloride. [4 marks]

(Do not forget about explanations of your steps)

Sodium reacts with Water as follows.

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

1.15 g of Sodium is allowed to react completely with Water. The resulting solution is diluted to 250 cm³. Calculate the concentration, in mol dm^–3, of the resulting Sodium Hydroxide solution.

[3 marks]

Determine the volume of 1.50 mol dm^–3 Hydrochloric Acid that would react with exactly 1.25 g of Calcium Carbonate. [3 marks]

Calculate the volume of Carbon Dioxide, measured at 273 K and

1.01×10⁵ Pa, which would be produced when 1.25 g of Calcium Carbonate reacts completely with the Hydrochloric Acid. [4 marks]

An organic compound, A, containing only the elements Carbon, Hydrogen and Oxygen was analysed.

(a) A was found to contain 54.5% C and 9.1%H by mass, the remainder being Oxygen. Determine the empirical formula of the compound. [3 marks]

(b) A 0.230 g sample of A, when vaporised, had a volume of 0.0785 dm³ at 95^oC and 102 kPa. Determine the relative molecular mass of A. [3 marks]

(c) Determine the molecular formula of A using your answers from parts (a) and (b). [1 mark]

[7 marks total]

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7