StudentAidUnit 5: Unit 5: States and Phases of Matter — Mcqs
11th Class Chemistry · Unit 5: States and Phases of Matter
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1.London dispersion forces are the only forces present among:
2.When the vapour pressure of a liquid equals the external pressure, what phenomenon occurs?
3.When water freezes at 0°C, its density decreases due to:
4.Which of the following is the correct sequence of increasing DeltaH_v values of substances mentioned?
5.Surface tension of a liquid is due to:
6.Which change of state involves overcoming only London dispersion forces?
7.In which of the following substances are London dispersion forces the only significant intermolecular forces present?
8.Which of the following is a characteristic property of crystalline solids?
9.Which of the following liquids would you expect to have the highest viscosity at a given temperature?
10.Which type of intermolecular force is present in all types of molecules regardless of their polarity?
11.Liquid crystals exhibit properties:
Properties and state of matter
12.Which state of matter exists only within a narrow range of temperature and pressure?
13.Why can gases be compressed easily?
Gas Laws
14.Which one of the following effects explains the cooling during the sudden expansion of a gas?
15.What is the relation between volume and pressure according to Boyle's Law?
16.Which of the following statements about ideal gases is true?
17.According to Avogadro's Law, volume is directly proportional to:
18.What is the unit of the ideal gas constant 'R' when pressure is in atm and volume in dm^3?
19.The ideal gas equation is given as:
20.What is the rearranged form of the ideal gas equation to calculate molar mass (M) of a gas?
Properties of Liquids
21.Which of the following statements is true about diffusion in liquids?
22.What causes the lower compressibility of liquids compared to gases?
23.Liquids are approximately how many times less compressible than gases?
24.According to kinetic molecular theory, liquid molecules are:
25.The expansion of liquids increase with temperature is:
26.What happens to the kinetic energy of liquid molecules when cooled?
Boiling Point
27.Which of the following halogens has the highest boiling point?
28.Which hydrocarbon has a higher boiling point due to longer chain length?
29.Which of the following has the lowest boiling point among pentane isomers?
Intermolecular Forces
30.Which of the following compounds exhibits permanent dipole-permanent dipole interactions?
31.Which of the following is a polar molecule that shows permanent dipole interactions?
32.What causes the polarity in a molecule like CHCl3?
Hydrogen Bonding
33.What type of force is hydrogen bonding?
34.Which of the following is essential for hydrogen bond formation?
35.What else is required on the electronegative atom for hydrogen bonding besides bonding to H?
Properties of Water
36.Why can a water molecule form two hydrogen bonds on average?
37.Why is HF less acidic compared to HCl, HBr, and HI?
38.What happens to the volume of water when it freezes?
39.Why does ice float on water?
40.What type of structure do water molecules form in ice?
41.What property of water allows aquatic life to survive under frozen surfaces?
42.What is the value of water's enthalpy of vaporization?
43.Why is water's surface tension so high?
44.Which of the following contributes to water's high viscosity?
Surface Tension
45.What causes surface tension in liquids?
46.Surface tension usually ___ with increasing temperature.
47.Why do liquid droplets tend to be spherical in shape?
Viscosity
48.What is the SI unit of viscosity?
49.Which of the following has greater viscosity than water?
Evaporation and Vapour Pressure
50.Earthenware pots keep water cool because:
51.What is vapour pressure?
52.At equilibrium in a closed system, which two processes occur at the same rate?
53.Why does acetone feel colder than water when poured on skin?
54.When does a liquid start boiling?
55.What is the effect of decreasing external pressure on boiling point of a liquid?
56.Why does water boil at 69°C on Mount Everest?
57.What is the role of a pressure cooker in boiling water?
Heat of Fusion
58.The value of molar heat of fusion for water is:
Heat of Vaporization
59.Which of the following has the lowest molar heat of vaporization?
60.How does heat of vaporization affect matter?
Properties of Solids
61.Why is the compression of solids not possible?
62.What happens to the particles in a solid when the temperature increases?
63.In solids, the particles mainly have which type of motion?
64.Which of the following is a characteristic of crystalline solids?
65.When a crystalline solid is broken, it does so along specific planes. These planes are known as:
66.The shape in which a crystal usually grows is called its:
Amorphous Solids
67.Amorphous solids are typically:
68.Which of the following materials is an example of an amorphous solid?
Crystalline Solids
69.What happens to the shape of a NaCl crystal when 10% urea is present in its solution?
Liquid Crystals
70.Which of the following best describes the molecular arrangement in liquid crystals?
71.What type of molecular shape is commonly found in liquid crystals?
72.Liquid crystals exhibit properties of:
73.Which of the following is a unique optical property of liquid crystals?
74.In which device are liquid crystals most commonly used?
75.Why are cholesteric liquid crystals useful in medical diagnostics?
76.Liquid crystals are used in thermometers because:
77.Which of the following is NOT a property of liquid crystals?