List of practice Questions

A driver of a car travelling at \(52\) \(km \;h^{–1}\) applies the brakes Shade the area on the graph that represents the distance travelled by the car during the period.
Which part of the graph represents uniform motion of the car?

Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.

Arrange the following substances in increasing order of forces of attraction between the particles— water, sugar, oxygen.

What is the physical state of water at—
(a) 25°C
(b) 0°C
(c) 100°C ?

Give two reasons to justify—
(a) Water at room temperature is a liquid.
(b) An iron almirah is a solid at room temperature.

Why is ice at 273K more effective in cooling than water at the same temperature?

Classify the following into elements, compounds and mixtures.
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood

Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of a candle

What produces more severe burns, boiling water or steam?

A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.

When 3.0g of carbon is burnt in 8.00g oxygen, 11.00g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00g of carbon is burnt in 50.0g of oxygen? Which law of chemical combination will govern your answer?

Name A,B,C,D,E and F in the following diagram showing change in its state

What are polyatomic ions? Give examples.

Write the chemical formulae of the following.
(a)Magnesium chloride
(b)Calcium oxide
(c)Copper nitrate
(d)Aluminium chloride
(e)Calcium carbonate

Give the names of the elements present in the following compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate.

Which separation techniques will you apply for the separation of the following?

(a) Sodium chloride from its solution in water
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride
(c) Small pieces of metal in the engine oil of a car
(d) Different pigments from an extract of flower petals
(e) Butter from curd
(f) Oil from water
(g) Tea leaves from tea
(h) Iron pins from sand
(i) Wheat grains from husk
(j) Fine mud particles suspended in water

Calculate the molar mass of the following substances.
(a) Ethyne, \(C_2H_2\)
(b) Sulphur molecule, \(S_8\)
(c) Phosphorus molecule, \(P_4\) (Atomic mass of phosphorus= 31)
(d) Hydrochloric acid, \(HCl\)
(e) Nitric acid, \(NO_3\)

Compare the properties of electrons, protons and neutrons.

Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

What are the limitations of J.J. Thomson’s model of the atom?