221. Which of the following is not soluble in water?

1. Lead sulphate
2. Zinc sulphate
3. Potassium sulphate
4. Sodium sulphate

Option “A” is correct
Lead Sulphate is not soluble in water.
222. The main constituent of biogas is –

1. Oxygen
2. Methane
3. Acetic acid
4. Methyl alcohol

Option “B” is correct
223. The pH of human blood is between –

1. 6.5–7
2. 7.35–7.45
3. 8–9
4. 4.5–5

Option “B” is correct
The pH of human blood is between 7.35 to 7.45.
224. Isotope 14C6 is associated with-

1. For cancer diagnosis
2. Determining the age of the earth
3. Determining the age of fossil
4. For traler technology

Option “C” is correct
This theory was given by Willard Frank Libby in 1949. To determine the age of wood and bones (the time which elapsed after the death of plant) is called Ratio Carbon Dating. The Half-life of Carbon 14 is 5,730 + 40 years.
225. Because of impurities the boiling point of a liquid-

1. Increases
2. Decreases
3. Remains constant
4. They are not related

Option “A” is correct
The boiling point of a liquid is the temperature at which its vapour pressure is equal to the pressure of the gas above it. Generally impurities increases the boiling point of liquid.
226. What is the process of rust forming on iron called?

1. Rusting
2. Crystallisation
3. Shovel
4. Spade

Option “A” is correct
Rusting is the process of rust forming on iron. In rusting, the red or orange coating that forms on the surface of iron when exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation.
227. The most abundant metal in the Earth’s crust is the following?

1. Zinc
2. Copper
3. Aluminium
4. Iron

Option “C” is correct
Most abundant element is Oxygen followed by Silicon .Both of these are non-metal. Silicon is followed by Aluminium which is most abundant metal.
228. Name the gas used in preparation of bleaching powder –

1. Oxygen
2. Hydrogen
3. Nitrogen
4. Chlorine

Option “D” is correct
The chlorine gas is used to react with the caustic soda in preparation of bleaching powder.
229. The depletion in Ozone layer is caused by ___________.

1. Nitrous oxide
2. Carbon dioxide
3. Chlorofluorocarbons
4. Methane

Option “C” is correct
The ozone layer is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet (UV) radiation. The depletion in Ozone layer is caused by Chlorofluorocarbons.
230. When water itself combines chemically with some element or mineral it is called –

1. Carbonation
2. Desalination
3. Hydration
4. Oxidation

Option “C” is correct
When water itself combines chemically with some element or mineral called hydration.
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11 thoughts on “Chemistry”

  6. Dolly

    I Love chemical…it’s my favourite subject..mere iss mein se hmesha hi boht ache marks aate hai….and my interest is also in chemistry…

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