Question

Ms Deepika conducted a few experiments to explain the properties of metals and non-metals. She set up the experiments as shown in the given figure.

She noted the observation as:
(I) No reaction will take place in beakers (iv) and (v).
(II) Hydrogen gas will be evolved in beakers in (i), (ii) and (iii).
(III) A vigorous reaction will take place in beaker (i) while no reaction will occur in beaker II.
(IV) Two different gases will be evolved in beaker (iv).
The correct observations are:

• A. II, III and IV only
• B. I and III only
• C. II and III only
• D. II and IV only

Answer 1

The correct option is B I and III only

$\bullet$ Charcoal (carbon) and copper metal do not react with hydrochloric acid, so observation I is correct.
$\bullet$ Magnesium does not react with cold water and thus there is no evolution of hydrogen gas in the beaker (ii). So observation II is incorrect.
$\bullet$ Sodium reacts vigorously with cold water whereas magnesium shows no reaction. Thus observation III is also correct.
$\bullet$ Charcoal show no reaction with hydrochloric acid thus observation IV is also incorrect.
$\bullet$ Therefore, only observations I and III are correct. Thus, option C is the right answer.