Priyanka B Solutions for Chapter: Is Matter Around Us Pure?, Exercise 1: Multiple Choice Questions MCQs

Tincture iodine used as antiseptic, is a solution of iodine dissolved into

Two substances A and B react to form a third substance ${\mathrm{AB}}_2$, according to the reaction. $\mathrm{A} + 2\mathrm{B}\to {\mathrm{AB}}_2$. The statement that is incorrect about the reaction is

(i) ${\mathrm{AB}}_2$ is an element.                      (ii) ${\mathrm{AB}}_2$ is a compound.

(iii) ${\mathrm{AB}}_2$ has a fixed composition    (iv) ${\mathrm{AB}}_2$ show the properties of A and B.

Which of the following are physical changes?

$\left(\mathrm{i}\right)$ LPG is burnt in kitchen      $\left(\mathrm{ii}\right)$ Tawa is heated

$\left(\mathrm{iii}\right)$ Kneaded flour is baked      $\left(\mathrm{iv}\right)$ water is poured over hot tawa

Which of the following are the chemical changes?

(i) an almirah gets rusted.

(ii) burning of candle.

(iii) melting of butter in a pan.

(iv) dissolving salt into water.

A mixture of sulphur and carbon disulphide is

Which of the following are the physical changes?

(i) melting of iron.
(ii) bending of iron rod.
(iii) rusting of iron.
(iv) iron is dropped into concentrated hydrochloric acid.

Which of the following are compounds?

To prepare $10\%$ (by mass) solution of common salt in water, we will take