Chapter 1: Moles and equations
8 Give all answers to 3 significant figures. a 1.20 dm3 of hydrogen chloride gas was dissolved in 100 cm3 of water. i How many moles of hydrogen chloride gas are present? ii What was the concentration of the hydrochloric acid formed? b 25.0 cm3 of the acid was then titrated against sodium hydroxide of concentration 0.200 mol dm–3 to form NaCl and water:
[1] [2]
H2O + NaCl
NaOH + HCl
i How many moles of acid were used? ii Calculate the volume of sodium hydroxide used.
[2] [2] Total = 7
9 Give all answers to 3 significant figures. 4.80 dm3 of chlorine gas was reacted with sodium hydroxide solution. The reaction taking place was as follows: Cl2(g) + 2NaOH(aq)
NaCl(aq) + NaOCl(aq) + H2O(l)
a How many moles of Cl2 reacted? b What mass of NaOCl was formed? c If the concentration of the NaOH was 2.00 mol dm–3, what volume of sodium hydroxide solution was required? d Write an ionic equation for this reaction.
[1] [2] [2] [1] Total = 6
10 Calcium oxide reacts with hydrochloric acid according to the equation: CaO + 2HCl
CaCl2 + H2O
a What mass of calcium chloride is formed when 28.05 g of calcium oxide reacts with excess hydrochloric acid? b What mass of hydrochloric acid reacts with 28.05 g of calcium oxide? c What mass of water is produced?
[2] [2] [1] Total = 5
11 When ammonia gas and hydrogen chloride gas mix together, they react to form a solid called ammonium chloride. a Write a balanced equation for this reaction, including state symbols. b Calculate the molar masses of ammonia, hydrogen chloride and ammonium chloride. c What volumes of ammonia and hydrogen chloride gases must react at r.t.p. in order to produce 10.7 g of ammonium chloride? (1 mol of gas occupies 24 dm3 at r.t.p.)
[2] [3] [3]
Total = 8
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