Complete the following by selecting the correct option from the choices given.

(i) The indicator which does not change colour on passage of HCl gas is ………….. [methyl orange, moist blue litmus, phenolphthalein].

(ii) The acid which cannot act as an oxidizing agent is …………… [conc. H₂SO₄, conc. HNO₃, conc. HCl]

Fill in the blanks with the choices given in the bracket:

When sodium chloride is heated with concentrated sulphuric acid below 200°C, one of the products formed is …………… [sodium hydrogen sulphate / sodium sulphate / chlorine]

State one observation for the following:

A small piece of zinc is added to dilute hydrochloric acid.

Hydrogen chloride gas is prepared in the laboratory using conc. H₂SO₄ and NaCl. Answer the questions that follow based on this reaction.

(i) Give the balanced chemical equation for the reaction with suitable condition[s] if any.

(ii) Why is concentrated sulphuric acid used instead of conc. nitric acid.

(iii) How is the gas collected.

(iv) Name the drying agent not used for drying the gas.