Is Matter Around Us Pure - Practice for Everyone

1.

Which of the following statements are true for pure substances?

(a) (i) and (ii)

(b) (i) and (iii)

(c) (iii) and (iv)

(d) (ii) and (iii)

2.

Which of the following is a physical change?

(a) iron fillings and Sulphur heated together

(b) iron exposed to rain for a long time

(c) burning of paper

(d) sublimation of ammonium chloride

3.

When Sulphur is mixed with carbon disulphide it forms a solution. The particle size of Sulphur is less and 1nm. Which of the following statements is true about this?

(a) Sulphur forms a colloidal solution in carbon disulphide and shows the Tyndall effect.

(b) Sulphur forms a suspension and shows the Brownian movement.

(c) Sulphur forms a true solution and does not show the Tyndall effect

(d) Carbon disulphide reacts with Sulphur and forms a compound.

4.

Which of the following are chemical changes?

(a) (ii) and (iii)

(b) (i), (iii) and (iv)

(c) (i), (ii) and (iii)

(d) (i), (ii) and (iv)

5.

Tincture of iodine has antiseptic properties. This solution is made by dissolving

(a) iodine in potassium iodide

(b) iodine in Vaseline

(c) iodine in water

(d) iodine in alcohol

6.

Which of the following statements concerning this reaction are incorrect?

(a) (i), (ii) and (iii)

(b) (ii), (iii) and (iv)

(c) (i), (iii) and (iv)

(d) (iii) and (iv)

7.

Two chemical species X and Y combine to form a product P which contains both X and Y. X + Y -- > P, X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y, and P are correct?

(a) (i), (ii) and (iii)

(b) (i), (ii) and (iv)

(c) (ii), (iii) and (iv)

(d) (i), (iii) and (iv)

8.

Which of the following is not a property of a metal?

(a) lustre

(b) bad conductor of heat and electricity

(c) sonorous

(d) malleable

9.

Which of the following is not a metalloid?

(a) silicon

(b) antimony

(c) germanium

(d) vanadium

10.

Identify the incorrect statement.

(a) Carbon, hydrogen, oxygen, nitrogen, Sulphur, chlorine, bromine, iodine, etc. are some examples of non-metals.

(b) Metalloids are lustrous, brittle and bad conductors of electricity and heat.

(c) Metalloids are elements that have properties that fall somewhere between those of metals and non-metals.

(d) There are 118 elements known at present out of which 92 are naturally occurring and the rest are man-made.

11.

Assertion (A): Colloids are heterogeneous mixtures and scatter light. Reason (R): Colloid are heterogeneous mixtures with particle sizes too small to be seen with the naked eye, but are big enough to scatter light.