CHEMISTRY DRILL

Holidays are almost over for most of us. Lets see how much chemistry you can remember.

on your marks, set,.......................DRILL!





                                                              DRILL

        1.       Which one of the following changes is physical? (a)     Adding iron filing to aerated water (b) Adding sodium metal to water  (C)  Cooling solution of iron (II) sulphate to obtain the hydrated salt  (d) Cooling water to obtain ice (e)  Burning the domestic gas (Utility gas) for cooking.

2.       Which of the following processes does NOT lead to a chemical change? (a)Stirring iron in sulphur (VI) acid (b)  Stirring sodium carbonate in water  (c)  Stirring glucose in concentrated sulphur (VI) acid  (d) Mixing Sulphur (VI) acid with potassium carbonate (e) Titrating an acid against a base

3.       In an experiment, which of the following observations would suggest that a solid sample is a mixture? The (a) Solid can be ground to a fine powder (b) Density of the solid is 2.25g dm^-3 (c) Solid begins to melt at 573K but not completely melted until 648K (d) Solid absorbs moisture from the atmosphere and turns into a liquid (e) Solid melts at 300K

4.       Which of the following substances is a mixture? (a) Granulated sugar (b) Sea-water (c) Sodium chloride (d) Iron fillings

5.       Which of the following would support the conclusion that a solid sample is a mixture? (a) The solid can be ground to a fine powder (b) The density of the solid is 2.25g dm^-3 (c) The solid has a melting range of 300^oC to 375^oC (d) The solid absorbs moisture from the atmosphere

6.       Which of the following is a physical change? (a) The bubbling of chlorine into water (b) The bubbling of chlorine in a jar containing hydrogen (c) The dissolution of sodium chloride in water (d) The passing of steam over heated iron

7.       Changes in the physical states of a chemical substance T are shown in the scheme below:

                                                 Liquid T

               

                                 Z                                               Y

            Solid T                           X                  Gaseous T

The letters X, Y & Z respectively represent?

(a) Sublimation, condensation and freezing

(b) Sublimation, vapourization and solidification

(c) Freezing, condensation and sublimation

(d) Evaporation, liquefaction and solidification

8.       Which of the following substances is not a homogenous mixture? (a) Filtered sea water (b) Soft drink

(c) Flood water (d) Writing ink

9.       The dissolution of common salt in water is a physical change because: (a) The salt can be obtained by crystallization (b) The salt can be recovered by the evaporation of the water (c) Heat is not generated during mixing (d) The solution will not boil at 100^oC

A mixture of sand, ammonium chloride and sodium chloride is best separated by? (a) Sublimation followed by addition of water and filtration (b) Sublimation followed by addition of    water and evaporation (c) Addition of water followed by filtration and sublimation  (d) Addition of water followed by crystallization and sublimation.