Module 2 exam style questions (OCR A A Level Chemistry) Part 1

Why is ... an example of a salt? - The H+ ion in the acid has been replaced by a metal ion OR by a/an ... ion Write the equation for the reaction between ... Include state symbols. - Formulae Balance AND states Explain how the ... ion in aqueous *alkali* acts as a base when it neutralises *acid*. - Accepts a proton OR accepts H+ What term is given to the '•x H2O' part of the formula? - Water of crystallisation Explain what is meant by the term salt. - when the H+ in an acid is replaced by a metal ion OR an ammonium ion OR a + ion Why is ammonia acting as a base in this neutralisation? - accepts a proton OR accepts H+ Old samples of magnesium oxide become contaminated with magnesium carbonate. (i) Suggest how this contamination takes place. (ii) Explain, with the aid of equations, why the resulting solution contained only one dissolved compound of magnesium. - (i) MgO has reacted with CO2 (ii) MgO + 2HCl → MgCl2 + H2O MgCO3 + 2HCl → MgCl2 + CO2 + H2O both reactions form magnesium chloride/MgCl2 Define an acid. - proton donor Chewing chalk has been used for many years to combat excess stomach aci