Question

The reaction of metal with acid results in the formation of:
A. Only hydrogen gas
B. Only salt
C. Both salt and hydrogen gas
D. None of these

Answer 1

Hint: The reaction of metal and with acid is a displacement reaction. Displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. Both metals and nonmetals take part in displacement reactions.

Step by step answer: Let’s observe the following reactions in which a metal is reacting with an acid-
When Zinc reacts with hydrochloric acid it produces zinc chloride and hydrogen gas.
\[Z{n_{(s)}} + 2HC{l_{(aq)}} \to ZnC{l_2}_{(aq)} + {H_2}_{(g)}\]
\[\]
When magnesium reacts with hydrochloric acid it produces magnesium chloride and hydrogen gas.
\[M{g_{(s)}} + 2HC{l_{(aq)}} \to MgC{l_2}_{(aq)} + {H_2}_{(g)}\]
Here we can clearly observe that magnesium and zinc, which are metals, react with an acid and produce their chloride salt.
From the above examples we can conclude that Acids react with most metals to form a salt and hydrogen gas. Metals that are more active than acids can undergo a single displacement reaction.

Hence, option (c) is correct.

Additional Information: It is important to confirm that the evolve gas which is produced after reaction between acid and metal is hydrogen gas. To confirm this we can safely test for small quantities of hydrogen gas collected in a test tube by holding a burning splint near to the top of the test tube. The positive result is a squeaky pop sound as the hydrogen reacts with oxygen in the air in a small explosion
Hydrogen gas is highly flammable.

Note: Students may confuse in choosing the most appropriate answer. Here option (A) and (B) are also components of the product, but option (C) contains the most appropriate answer.