Question 61 : Glycerin is a polar compound. It boils at 290°C under l atm. It should be distilled under reduced pressure due to the reason that?
1. It decomposes at 290°C.
2. low pressure makes the liquid to boil at high temperature.
3. There are strong intermolecular forces between molecules of glycerin.
4. The reduced pressure decreases the boiling point of liquids.
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Question 62 : Ionic solids are characterized by?
1. Low melting points.
2. High vapour pressure.
3. Good conductivity in solid state.
4. Solubility in polar solvents.
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Question 63 : To cook the food at a high mountain is difficult as compared to sea level because?
1. The hydrogen bonding in water changes with the change of height.
2. The density of water decreases at the mountains.
3. The temperature at the top of the mountain is low.
4. The boiling point of water decreases at the mountains.
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Question 64 : oiling point increases with the presence of?
1. Covalent bond
2. lone pair
3. Double covalent bond
4. H—bonding
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Question 65 : The conversion of solid state directly into a gaseous state without passing through liquid state is called?
1. Evaporation
2. Freezing
3. Sublimation
4. Boiling
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Question 66 : When α ? β ? γ ? 90° then the system is said to be?
1. Triclinic
2. Hexagonal
3. Trigonal
4. Monodlinic
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Question 67 : When α = β = 90° and γ = 120° then the system is said to be?
1. Hexagonal
2. Monodinic
3. Trigonal
4. Orthorhombic
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Question 68 : Which of the following pair form cubic crystals?
1. ZnSO4 and NiSO4
2. NaF and MgO
3. CaCO3 and NaNO3
4. ZnSO4 and NaNO3
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Question 69 : I2 is the example of?
1. Atomic crystal
2. Ionic crystal
3. Covalent crystal
4. Molecular crystal
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Question 70 : Diamond is the example of?
1. Ionic crystal
2. Covalent Crystal
3. Atomic crystal
4. Molecular crystal
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