Is matter around us pure Worksheet-8
A. Yellow coloured sulphur will float at the surface of solution
B. Sulphur will dissolve completely forming true solution
C. Yellow ppt of sulphur will be formed and supernatant solution will be colourless
D. The solution will become dark yellow in colour due to dissolution of more sulphur in it
A. There would have been no plants as atmospheric nitrogen is fixed by microorganisms and used by plants
B. Combustion once started would never stop
C. No effect as we inhale oxygen and not nitrogen
D. Oxides of nitrogen which are pollutants would not have been formed
A. No unit B. g/L C. Kg /L D. mg/ml
A. Colloidal solution
D. Both are immiscible liquids
A. Bread B. Butter C. Smoke D. Boot polish
A. Sodium chloride and iodine crystals
B. Potassium chloride and iodine crystals
C. Ammonium chloride and iodine crystals
D. Lithium chloride and camphor
A. Fractional distillation
B. Sublimation as carbon tetrachloride sublimes
C. Separating funnel
D. Steam distillation
A. No B. Yes C. Can’t say
A. Elements cannot be separated by physical methods of separation
B. It has a sharp melting point
C. Sodium chloride is formed by the chemical combination of sodium and chlorine
D. All of these
(a) Carbon dioxide gas dissolved in water.
(b) Air containing suspended particles.
(c) Soap bubbles formed by blowing air into soap solution.
A. (a) Homogeneous (b) Heterogeneous (c) Heterogeneous
B. (a)Homogeneous (b) Homogeneous (c) Heterogeneous
C. (a) Heterogeneous (b) Homogeneous (c) Heterogeneous
D. (a) Heterogeneous (b) Heterogeneous (c) Heterogeneous
A. Simple distillation
B. Fractional distillation
C. Steam distillation
A. Hydrogen and oxygen combine in fixed ratio by mass in water
B. Water is a liquid whereas oxygen and hydrogen are gases
C. Oxygen supports combustion where as water is used as fire extinguisher
D. Properties of water are different from its constituents
E. All of these
Explanation: The yellow precipitate of sulphur will settle at the bottom of the tube and the solution collected above the precipitate will be colourless.
Explanation: The rust is a brown chemical compound known as hydrated ferric oxide (Fe2O3xH2O). Iron undergoes chemical change.
Explanation: The role of nitrogen in air is to dilute the combustion effect of oxygen since nitrogen does not support combustion. Had nitrogen been absent, the combustion once started would never stop. You can well imagine as to what might have happened to us.
Explanation: Mass percent has no units as it is simply a ratio.
Explanation: Mustard oil and water are immiscible liquids. They can form emulsion in the presence of emulsifiers.
Explanation: Smoke, dust storm, haze are the colloidal solution in which solid particles are dispersed in air.
Explanation: Ammonium chloride and iodine crystals.
Explanation: Both are immiscible liquids. The separation can be done by the use of a separating funnel.
Explanation: No, it is not possible because alcohol (ethyl alcohol) and water are miscible. Separating funnel is used for separating immiscible liquids
Explanation: The two elements sodium and chlorine have combined with each other by chemical reaction to form sodium chloride (NaCl) which is a chemical compound. Since these elements cannot be separated from each other by any physical processes of separation, sodium chloride is a pure substance.
Explanation: (a) homogeneous (b) heterogeneous (c) heterogeneous
Explanation: The separation can be done by the process of simple distillation. The vapours of the liquid A will be formed at the temperature of 60°C. They will pass through the condenser and will collect as distillate. The liquid B with higher boiling point will remain in the flask.
Explanation: The properties of water are different from its constituents. Water has fire extinguishing property where as oxygen supports combustion. Hydrogen and oxygen are gases whereas water is a liquid. Hydrogen and oxygen combine in fixed ratio by mass.