Questions 1. Why should curd and sour substances not be kept in brass and copper vessels? Ans: Curd & Sour substances are acidic in nature, it will react with brass & copper these acidic substances combine with metal. This reaction turns food to poison which damage people’s health. 2. Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas? Ans: When an acid reacts with any metal, salt and hydrogen gas are formed. Metal + Acid → Salt + Hydrogen gas 3. Metal compound A reacts with dilute hydrochloric acid to produce effervescence(bubbles in liquid). The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. Ans: As metal compound released is Calcium Chloride the gas evolved here is CO2. Hence metal A should be Calcium Carbonate. Hence the...