Why does magnesium powder reacts much more rapidly than magnesium ribbon with dilute sulphuric acid

Q.

Write word equations and then balanced equations for the reaction taking

place when −

(a) dilute sulphuric acid reacts with zinc granules.

(b) dilute hydrochloric acid reacts with magnesium ribbon.

(c) dilute sulphuric acid reacts with aluminium powder.

(d) dilute hydrochloric acid reacts with iron filings.

Q. Dilute hydrochloric acid reacts with magnesium ribbon:

Q. Reaction of magnesium ribbon with dilute sulphuric acid to form magnesium sulphate and hydrogen is a combination reaction.

Q. Suggest a reason for each observation given below.
i) In fireworks, powdered magnesium is used rather than magnesium ribbon.
ii) Zinc and dilute $H_{2}S{O}_4$ react much more quickly when a few drops of copper sulphate solution are added.
iii) The reaction between magnesium carbonate and dilute hydrochloric acid speeds up when some concentrated $HCl$ is added.

Q. The products obtained when very dilute nitric acid (${\text{HNO}}_3$) reacts with magnesium are and hydrogen gas.