Free Solutions and Colloids MCQs with Answers

101. The osmotic pressure of dilute solution is given below by relationship:

• A. π = iCRT
• B. π = RCT/M
• C. π = nRT/V
• D. π = PV = nRT

Explanation: The correct relationship for the osmotic pressure of a dilute solution is given by the equation π = RCT/M. This equation shows that osmotic pressure is directly proportional to the temperature (T) and molar concentration (C) of the solute, and inversely proportional to the molar mass (M). The formula accounts for the behavior of the solution as it approaches ideal conditions, where R is the ideal gas constant.Option A is incorrect because it includes the van 't Hoff factor, which is not needed for non-electrolyte dilute solutions. Options C and D are incorrect as they refer to the ideal gas law, which is not applicable for calculating osmotic pressure in solutions.

102. Which of the following solution will have

• A. 1 molar solution of urea
• B. 1 molar solution of glucose
• C. 1 molar solution of sodium chloride
• D. 1 molar solution of magnesium chloride

Explanation: The correct answer is the 1 molar solution of urea. Urea is a non-electrolyte, meaning it does not dissociate into ions in solution. This makes it contribute to solution properties as a single particle per molecule, unlike electrolytes that increase the number of particles by dissociating into ions.Glucose, similar to urea, is a non-electrolyte and does not dissociate, but the question may be looking for the option that contrasts with electrolytes like NaCl and MgCl2. Sodium chloride dissociates into two ions, and magnesium chloride dissociates into three ions, increasing their effective concentration in terms of particle number, thus affecting colligative properties differently.

103. Freezing point of a solution as compared to the solvent is:

• A. Lower
• B. Variable
• C. Higher
• D. Remain the same

Explanation: The freezing point of a solution is generally lower compared to the freezing point of the pure solvent. This happens because when a solute is added to a solvent, it disrupts the arrangement of the solvent particles, making it harder for them to form a solid structure. As a result, the solution needs to be cooled to a lower temperature in order to freeze.

104. According to Raoult's law relative lowering of vapour pressure for a solution is equal to:

• A. mole fraction of the solvaent
• B. Mole fraction of the solute
• C. Moles of a solvant
• D. Moles of the solvent

Explanation: According to Raoult's law, the relative lowering of vapor pressure is equal to the mole fraction of the solute in the solution.Raoult's law describes the relationship between the vapor pressure of a solvent in a solution and the vapor pressure of the pure solvent. It states that the relative lowering of vapor pressure (Δp/Ppure is equal to the mole fraction of the solute (x solute ).Mathematically, it can be expressed as:Δp/ Ppure =x solute

105. Which ion is present in the highest concentration in a 2 mole/cm3 solution of sodium sulfate?

• A. The hydrogen ion, H+
• B. The hydroxide ion, OH-
• C. The sodium ion, Na+ (aq)
• D. The sulphate ion, SO4-2 (aq).

Explanation: .Na+ ions will be present in the highest concentration since there are 2 moles of Na+ in each mole of Na2SO4, so the concentration of Na+ is 4 moles/cm3. Therefore, C is the correct answer.

106. 2% solution by weight of sodium chloride solution is prepared. The molality of the solution is:

• A. 0.34 molal
• B. 0.25 molal
• C. 2 molals
• D. 0.02 mol

Explanation: 2% solution by weight means 2 grams of NaCl is dissolved per 100 grams of water. No. of moles = given mass/ molar mass = 2/58.5= 0.034Molality = no of moles / mass of solution in kg= 0.034/0.1= 0.34 Molal

107. In one molal aqueous solution of C2H3OH the mole fraction of C2H5OH is :

• A. 0.1
• B. 0.9
• C. 0.0177
• D. 1.0

Explanation: Explanation for this question will be added soon.

108. To what volume in .... must 50.0ml of 3.50M H2SO4 be diluted in order to make 2 M H2SO4?

• A. 25
• B. 60.1
• C. 87.5
• D. 93.2

Explanation: The correct option is c 87.5 mL M1V1=M2V2 Where, M1⇒ Molarity of the initial solution = 3.5 M V1⇒ Volume of the initial solution = 50 mL M2⇒ Molarity of the resultant solution i.e. after dilution = 2 M V2⇒ Volume of the resultant solution 3.5×50=2×V2 V2=3.5×502=87.5 mL Therefore, the initial solution must be diluted to 87.5 mL

109. In the laboratory standard solution is prepared in?

• A. Conical flasks
• B. Beakers
• C. Volumetric flask
• D. Measuring cylinder

Explanation: Volumetric flasks, on the other hand, are specifically designed for accurate measurement of a specific volume and are the preferred choice for preparing standard solutions.

110. What is the ionic strength of 0.01M barium chloride solution :

• A. 0.03
• B. 0.02
• C. 0.04
• D. 0.01

Explanation: 0.01: This option is correct. The ionic strength is equal to 0.01. In this case, the concentration of both the barium ions (Ba2+) and chloride ions (Cl-) is 0.01 M. Since there is only one ion of each type, the sum of their concentrations gives the total ionic strength of the solution, which is 0.01 M. The ionic strength of a solution is a measure of the total concentration of ions in the solution. In this case, we have a 0.01 M barium chloride solution. To calculate the ionic strength, we need to consider the contribution of both the barium ions (Ba2+) and chloride ions (Cl-) to the total ionic concentration.