JEE Chemistry Solutions MCQs Set A

Question: “The importance of many pure substance in life depends on their composition.” Which of the following statement justify the above fact?

• a) All of the above.
• b) Concentration above 1.5 ppm can be poisonous
• c) 1.5 ppm of fluoride ions causes tooth decay
• d) 1 ppm of fluoride ions in water prevents tooth decay.

Answer: All of the above.

Question: Which of the following fluoride is used as rat poison?

• a) NaF
• b) CaF₂
• c) KF
• d) MgF₂

Answer: NaF

Question: Most of the processes in our body occur in

• a) liquid solution
• b) colloidal solution
• c) solid solution
• d) gaseous solution

Answer: liquid solution

Question: The term homogenous mixtures signifies that

• a) both composition and properties are uniform throughout the mixture
• b) its properties are uniform throughout the mixture
• c) its composition is uniform throughout the mixture
• d) neither composition nor properties are uniform throughout the mixture

Answer: both composition and properties are uniform throughout the mixture

Question:  Which of the following mixture is(are) called solution?

(i) water + ammonia   (ii) water + acetone
(iii) acetone + alcohol (iv) hexane + water

• a) (i), (ii) and (iii)
• b) (i) and (iv)
• c) (i), (iii) and (iv)
• d) (ii) and (iii)

Answer: (i), (ii) and (iii)

Question: Which of the following is a quantitative description of the solution?

• a) Molar
• b) Concentrated
• c) Dilute
• d) Saturated

Answer: Molar

Question:  When a solute is present in trace quantities the following expression is used

• a) Parts per million
• b) Milligram percent
• c) Gram per million
• d) Microgram percent

Answer: Parts per million

Question: Molarity of liquid HCl will be, if density of solution is 1.17 gm/cc

• a) 32.05
• b) 42.10
• c) 36.5
• d) 18.25

Answer: 32.05

Question:  1 M, 2.5 litre NaOH solution is mixed with another 0.5 M, 3 litre NaOH solution. Then find out the molarity of resultant solution

• a) 0.73 M
• b) 0.80 M
• c) 1.0 M
• d) 0.50 M

Answer: 0.73 M

Question: An X molal solution of a compound in benzene has mole fraction of solute equal to 0.2. The value of X is

• a) 3.2
• b) 2
• c) 14
• d) 1.4

Answer: 3.2

Question: The molarity of the solution containing 7.1 g of Na₂SO₄ in 100 ml of aqueous solution is

• a) 0.5 M
• b) 0.05 M
• c) 2 M
• d) 1 M

Answer: 0.5 M

Question: The vapour pressure of pure benzene at 25°C is 640 mm Hg and that of solution of solute A is 630 mm Hg. The molality of solution is

• a) 0.2 m
• b) 0.5 m
• c) 0.4 m
• d) 0.1 m

Answer: 0.2 m

Question: 4.0 g of NaOH is dissolved in 100 ml solution. The normality of the solution is

• a) 1.0 N
• b) 0.5 N
• c) 0.1 N
• d) 4.0 N

Answer: 1.0 N

Question: The molarity of pure water is

• a) 55.6 M
• b) 50 M
• c) 18 M
• d) 100 M

Answer: 55.6 M

Question: An aqueous solution of glucose is 10% in strength. The volume in which 1 g mole of it is dissolved, will be

• a) 1.8 litre
• b) 0.9 litre
• c) 9 litre
• d) 8 litre

Answer: 1.8 litre

Question: 1 g of NaCl is dissolved in 106g of the solution. Its concentration is

• a) 10 ppm
• b) 0.1 ppm
• c) 100 ppm
• d) 1 ppm

Answer:  10 ppm

Question: On adding a solute to a solvent having vapour pressure 0.80 atm, vapour pressure reduces to 0.60 atm. Mole fraction of solute is

• a) 0.25
• b) 0.50
• c) 0.75
• d) 0.33

Answer: 0.25

Question: 2.5 litres of NaCl solution contain 5 moles of the solute. What is the molarity?

• a) 2 molar
• b) 12.5 molar
• c) 5 molar
• d) 2.5 molar

Answer: 2 molar

Question: The mole fraction of the solute in one molal aqueous solution i

• a) 0.018
• b) 0.036
• c) 0.009
• d) 0.027

Answer: 0.018

Question: 5 ml of N HCl, 20 ml of N/2 H₂SO₄ and 30 ml of N/3 HNO₃ are mixed together and volume made to one litre. The normality of the resulting solution is

• a)

  

• b)

  

• c)

  

• d) None of othese

Answer:

Question: 25ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a titre value of 35ml. The molarity of barium  hydroxide solution was

• a) 0.07
• b) 0.28
• c) 0.14
• d) 0.35

Answer: 0.07

Question: Mole fraction of the solute in a 1.00 molal aqueous solution is

• a) 0.0177
• b) 1.7700
• c) 0.1770
• d) 0.0344

Answer: 0.0177

Question: What is the normality of a 1 M solution of H₃PO₄ ?

• a) 3.0 N
• b) 1.0 N
• c) 0.5 N
• d) 2.0 N

Answer: 3.0 N

Question: The volume of 4 N HCl and 10 N HCl required to make 1 litre of 6 N HCl are

• a) 0.67 litre of 4 N HCl and 0.33 litre of 10 N HCl
• b) 0.80 litre of 4 N HCl and 0.20 litre of 10 N HCl
• c) 0.50 litre of 4 N HCl and 0.50 litre of 10 N HCl
• d) 0.75 litre of 10 N HCl and 0.25 litre of 4 N HCl

Answer: 0.67 litre of 4 N HCl and 0.33 litre of 10 N HCl

Question: Molarity of H₂SO₄ is 18 M. Its density is 1.8 g/ml. Hence molality is

• a) 500
• b) 36
• c) 200
• d) 18

Answer: 500

Question: 200 ml of water is added to 500 ml of 0.2 M solution. What is the molarity of this diluted solution ?

• a) 0.1428 M
• b) 0.2897 M
• c) 0.5010 M
• d) 0.7093 M

Answer: 0.1428 M

Question: How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0M HNO₃ ? The concentrated acid is 70% HNO₃

• a) 45.0 g conc. HNO₃
• b) 70.0 g conc. HNO₃
• c) 90.0 g conc. HNO₃
• d) 54.0 g conc. HNO₃

Answer: 45.0 g conc. HNO₃

Question: For preparing 0.1 N solution of a compound from its impure sample of which the percentage purity is known, the weight of the substance required will be

• a) More than the theoretical weight
• b) Same as the theoretical weight
• c) Less than the theoretical weight
• d) None of these

Answer: More than the theoretical weight

Question:

• a)

  

• b)

  

• c)

  

• d) N

Answer:

Question: A solution made by dissolving 40 g NaOH in 1000 g of water is

• a) 1 molal
• b) 1 molar
• c) 1 normal
• d) None of these

Answer: 1 molal

Question: Which of the following concentration terms is/are ndependent of temperature?

• a) Molality and mole fraction
• b) Molality only
• c) Molarity and mole fraction
• d) Molality and normality

Answer: Molality and mole fraction

Question: A solution is prepared by dissolving 10 g NaOH in 1250 mL f a solvent of density 0.8 mL/g. The molality of the solution in mol kg^–1 is

• a) 0.25
• b) 0.008
• c) 0.2
• d) 0.0064

Answer:  0.25

Question: Which of the following units is useful in relating concentration of solution with its vapour pressure?

• a) mole fraction
• b) mass percentage
• c) parts per million
• d) molality

Answer: mole fraction

Question:  For mixture containing “four” components which of the following is correct in term of mole fraction?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following concentration unit is independent of temperature ?

• a) Molality
• b) Molarity
• c) Normality
• d) Formality

Answer: Molality

Question: Which of the following factor do not affect solubility of solid solute in liquid ?

• a) Pressure
• b) All of these
• c) Temperature
• d) Nature of solute

Answer: Pressure

Question: When a solid solute is added to the solvent, some solute dissolves and its concentration increases in solution. This process is known as ______. Some solute particles in solution collide with the solid solute particles and get separated out of solution. This process is known as ______.

• a) Dissolution, crystallization
• b) Saturation, crystallization
• c) Dissolution, saturation
• d) Crystallization, dissolution

Answer: Dissolution, crystallization

Question:

• a) Rate of dissolution = Rate of unsaturation
• b) Rate of dissolution = Rate of unsaturation
• c) Rate of dissolution = Rate of saturation
• d) Rate of crystallization = Rate of saturation

Answer: Rate of dissolution = Rate of unsaturation

Question: Which of the following statements is incorrect?

• a) The minimum amount of solute dissolved in a given amount of solvent is its solubility
• b) The solution which is in dynamic equilibrium with undissolved solute is the saturated solution
• c) An unsaturated solution is one in which more solute can be dissolved at the same temperature
• d) A solution in which no more solute can be dissolved at the same temperature and pressure is called a saturated solution

Answer: The minimum amount of solute dissolved in a given amount of solvent is its solubility

Question: On dissolving sugar in water at room temperature solution feels cool to touch. Under which of the following cases dissolution of sugar will be most rapid ?

• a) Powdered sugar in hot water
• b) Powdered sugar in cold water
• c) Sugar crystals in hot water.
• d) Sugar crystals in cold water

Answer: Powdered sugar in hot water

Question:

• a) Rate at which gaseous particles are striking the solution to enter it, decreases
• b) Rate at which gaseous particles are striking the solution to enter it, increases
• c) In figure (b) on compressing the gas number of gaseous particles per unit volume over the solution increases.
• d) In figure (a) assuming the state of dynamic equilibrium rate of gaseous particles entering and leaving the solution phase is same

Answer: Rate at which gaseous particles are striking the solution to enter it, decreases

Question: The statement “If 0.003 moles of a gas are dissolved in 900 g of water under a pressure of 1 atmosphere, 0.006 moles will be dissolved under a pressure of 2 atmospheres”, illustrates

• a) Henry’s law
• b) Raoult’s law
• c) Graham’s law
• d) Dalton’s law of partial pressure

Answer: Henry’s law

Question: According to Henry’s law, the amount of gas that will dissolve in blood plasma or any other liquid is determined by which of these factor?

• a) Solubility of the gas in the liquid.
• b) The total pressure of the gas mixture
• c) pH of the liquid
• d) The osmotic pressure of the gas mixture

Answer: Solubility of the gas in the liquid.

Question: Henry’s law constant of oxygen is 1.4 × 10^–3 mol. lit^–1. atm^–1 at 298 K. How much of oxygen is dissolved in 100 ml at 298 K when the partial pressure of oxygen is 0.5 atm?

• a) 2.24 mg
• b) 3.2 g
• c) 1.4 g
• d) 22.4 mg

Answer: 2.24 mg

Question: At equillibrium the rate of dissolution of a solid solute in a volatile liquid solvent is ______.

• a) equal to the rate of crystallisation
• b) zero
• c) greater than the rate of crystallisation
• d) less than the rate of crystallisation

Answer: equal to the rate of crystallisation

Question: A beaker contains a solution of substance ‘A’. Precipitation of substance ‘A’ takes place when small amount of ‘A’ is added to the solution. The solution is ______.

• a) supersaturated
• b) concentrated
• c) saturated
• d) unsaturated

Answer: supersaturated

Question: Maximum amount of a solid solute that can be dissolved in a specified amount of a given liquid solvent does not depend upon __________.

• a) Pressure
• b) Temperature
• c) Nature of solute
• d) Nature of solvent

Answer: Pressure

Question: Low concentration of oxygen in the blood and tissues of people living at high altitude is due to

• a) low atmospheric pressure
• b) high atmospheric pressure
• c) both low temperature and high atmospheric pressure
• d) low temperature

Answer: low atmospheric pressure

Question: Value of Henry's constant K_H _______.

• a) increases with increase in temperature.
• b) decreases with increase in temperature.
• c) remains constant
• d) first increases then decreases

Answer: increases with increase in temperature.

Question: The value of Henry's constant K_H is _______.

• a) greater for gases with lower solubility
• b) greater for gases with higher solubility
• c) constant for all gases
• d) not related to the solubility of gases

Answer: greater for gases with lower solubility

Question: Which of the followingfactor(s) affect the solubility of a gaseous solute in the fixed volume of liquid solvent ?

(i) Nature of solute (ii) Temperature (iii) Pressure

• a) (i) and (iii) at constant T
• b) (i) and (ii) at constant P
• c) (ii) and (iii) only
• d) (iii) only

Answer: (i) and (iii) at constant T

Question:  Which of the following graph is a correct representation of Henry’s law?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which is an application of Henry’s law?

• a) Soft drinks (soda)
• b) Bottled water
• c) Spray paint
• d) Filling up atire

Answer: Soft drinks (soda)

Question: Scuba divers may experience a condition called ______. To avoids this, the tanks used by scuba divers are filled with air diluted with _____

• a) Bends, Helium
• b) Cramps, Nitrogen
• c) Migrains, Hydrogen
• d) Nausea, Oxygen

Answer: Bends, Helium

Question: People living at high attitudes often reported with a problem of feeling weak and inability to think clearly. The reason for this is

• a) at high altitudes the partial pressure of oxygen is less than at the ground level
• b) at high altitudes the partial pressure of oxygen is more than at the ground level
• c) at high altitudes the partial pressure of oxygen is equal to at the ground level
• d) None of these

Answer:  at high altitudes the partial pressure of oxygen is less than at the ground level

Question: ____ a contemporary of Henry concluded independently that solubility of a gas in a liquid solution is a function of ____ of the gas.

• a) Dalton, partial pressure
• b) Mosley, partial pressure
• c) Dalton, temperature
• d) Mosley, temperature

Answer: Dalton, partial pressure

Question: Raoult’s law becomes a special case of Henry’s law when

• a)

  

• b)

  

• c)

  

• d) None of these 

Answer:

Question: Iodine and sulphur dissolve in

• a) carbon disulphide
• b) water
• c) benzene
• d) ethanol

Answer: carbon disulphide

Question: The liquids at a given temperature vapourise and under equilibrium conditions the pressure exerted by the vapours of the liquid over the liquid phase is called

• a) vapour pressure
• b) atmospheric pressure
• c) osmotic pressure
• d) hydrostatic pressure

Answer: vapour pressure

Question: Which of the following fluoride is used as rat poison?

• a) NaF
• b) KF
• c) CaF₂
• d) MgF₂

Answer:  NaF