Answer
(a) $2HCl(aq) + 2K(s) -- \gt H_2(g) + 2KCl(aq)$
(b) $2HCl(aq) + Ca(s) -- \gt H_2(g) + CaCl_2(aq)$
(c) $2HCl(aq) + 2Na(s) -- \gt H_2(g) + 2NaCl(aq)$
(d) $2HCl(aq) + Sr(s) -- \gt H_2(g) + SrCl_2(aq)$
Work Step by Step
An acid-metal reaction follows the pattern:
$Acid + Metal --\gt Hydrogen$ $gas + Salt$
Therefore, in this type of reaction, the hydrogen in the acid will produce hydrogen gas, and the conjugate base will make an ionic compound (salt) with the metal.
1. Write the reaction following that pattern.
2. Balance the chemical equation.