Q1. The gas used to inflate the tyres of an aircraft is-
Q2. Which of these consists carbon?
Q3. Of how many carats is the pure gold?
Q4. Octane number is a measure of the quality of-
(a) Edible oils
(c) Kerosene oil
(d) Perfumed oil
Q5. Table salt (NaCI) is a product of-
(a) Weak acid ad weak base
(b) Strong acid and strong base
(c) Weak acid and strong base
(d) Strong acid and weak basic
Q6. Which gas is mixed with Oxygen for respiration by divers in deep sea?
Q7. The chemical formula of Heavy Water is?
(a) H_2 O
(b) D_2 O
(c) H_2 CO_3
(d) H_2 S
Q8. The atomic nucleus was discovered by:
Q9.Which one of the following mixtures is homogeneous?
(a)Starch and sugar
(b)Methanol and water
(c)Graphite and charcoal
(d)Calcium carbonate and calcium bicarbonate
Q10. Polymer of Natural Rubber is-
Sol. Nitrogen gas is used in the tyres of an aeroplane. This is because the nitrogen gas does not support combustion and can assist in preventing wheel fire when the aircraft lands .
Sol. Coal minerals are divided mainly into four types on the basis of the percentage of Carbon amount-
Peat, Lignite, Bituminous and Anthracite.
Sol. It is an extension of the older carat (Karat in North American spelling) system of denoting the purity of gold by fractions of 24, such as ’18 carat’ for an alloy with 75% (18 parts per 24) pure gold by mass.
Sol. Quality of petrol is expressed by octane number and that of diesel by cetane number.
Sol. The compounds formed after reaction between the strong base and strong acid are known as neutral salt. Sodium chloride (NaCI) is an example of neutral which is salt also known as Table Salt.
Sol. Heliox is a breathing gas composed of a mixture of Helium (He) and Oxygen (O2). This is frequently used for respiration by divers in the deep sea.
Sol. Heavy water (D2 O) Deuterium Oxide is used as a moderator and coolant in nuclear reactors because it slows down neutrons effectively and also has a low probability of absorption of neutrons.
Sol. The nucleus is a very dense region consisting of protons and neutrons at the centre of an atom. It was discovered in 1911 as a result of Ernest Rutherford’s interpretation of the 1909 Geiger-Marsden gold foil experiment.
Sol. A mixture of methanol (a liquid) and water (a liquid) is homogeneous.
Sol. Polymerization is the process of joining together a large number of small molecules to make a number of the very large molecule. Natural rubber is the natural polymer of Isoprene.