Q. In a solution of a non-volatile solute, how does the vapor pressure compare to that of the pure solvent?
A.
Higher than the pure solvent
B.
Lower than the pure solvent
C.
Equal to the pure solvent
D.
Depends on the temperature
Show solution
Solution
The presence of a non-volatile solute lowers the vapor pressure of the solvent compared to that of the pure solvent.
Correct Answer: B — Lower than the pure solvent
Learn More →
Q. In a solution of two volatile components A and B, if the mole fraction of A is 0.6, what is the vapor pressure of the solution if the vapor pressure of pure A is 100 mmHg and that of pure B is 50 mmHg?
A.
80 mmHg
B.
90 mmHg
C.
70 mmHg
D.
60 mmHg
Show solution
Solution
Using Raoult's Law, the vapor pressure of the solution is P_total = (0.6 * 100) + (0.4 * 50) = 60 + 20 = 80 mmHg.
Correct Answer: B — 90 mmHg
Learn More →
Q. In a solution of volatile components A and B, if the vapor pressure of A is 80 mmHg and that of B is 20 mmHg, what is the total vapor pressure?
A.
100 mmHg
B.
80 mmHg
C.
60 mmHg
D.
20 mmHg
Show solution
Solution
The total vapor pressure of a solution is the sum of the partial vapor pressures of its components: 80 mmHg + 20 mmHg = 100 mmHg.
Correct Answer: A — 100 mmHg
Learn More →
Q. In an ideal solution, the enthalpy of mixing is:
A.
Positive
B.
Negative
C.
Zero
D.
Varies with concentration
Show solution
Solution
In an ideal solution, the enthalpy of mixing is zero, indicating no heat is absorbed or released during mixing.
Correct Answer: C — Zero
Learn More →
Q. Solve for x: 3(x - 1) = 2(x + 4).
Show solution
Solution
Expanding gives 3x - 3 = 2x + 8. Rearranging gives x = 11.
Correct Answer: A — -10
Learn More →
Q. Solve for x: 3(x - 2) = 12.
Show solution
Solution
Dividing both sides by 3 gives x - 2 = 4, thus x = 6.
Correct Answer: C — 6
Learn More →
Q. Solve for x: 5x + 2 = 3x + 10.
Show solution
Solution
Subtracting 3x from both sides gives 2x + 2 = 10, then subtracting 2 gives 2x = 8, leading to x = 4.
Correct Answer: A — 4
Learn More →
Q. Solve for x: x^2 - 9 = 0.
Show solution
Solution
The equation factors to (x - 3)(x + 3) = 0, giving solutions x = 3 and x = -3.
Correct Answer: D — ±3
Learn More →
Q. Solve for y: 4y + 8 = 24.
Show solution
Solution
Subtracting 8 from both sides gives 4y = 16, then dividing by 4 gives y = 4.
Correct Answer: B — 3
Learn More →
Q. The quadratic equation x^2 + 4x + k = 0 has roots that are both negative. What is the condition on k?
A.
k < 0
B.
k > 0
C.
k < 4
D.
k > 4
Show solution
Solution
For both roots to be negative, the sum of roots (4) must be positive and the product (k) must be positive, hence k > 0.
Correct Answer: C — k < 4
Learn More →
Q. The quadratic equation x^2 - 6x + k = 0 has roots that are both positive. What is the condition on k?
A.
k > 0
B.
k < 0
C.
k > 9
D.
k < 9
Show solution
Solution
For both roots to be positive, k must be greater than the square of half the coefficient of x: k > (6/2)^2 = 9.
Correct Answer: C — k > 9
Learn More →
Q. The roots of the equation 2x^2 - 4x + k = 0 are 1 and 2. Find the value of k.
Show solution
Solution
Using Vieta's formulas, sum of roots = 1 + 2 = 3 = -(-4)/2 => k = 2*1*2 = 4.
Correct Answer: C — 6
Learn More →
Q. What does Raoult's Law state about the vapor pressure of a solution?
A.
It is directly proportional to the mole fraction of the solvent.
B.
It is inversely proportional to the mole fraction of the solute.
C.
It is equal to the vapor pressure of the solute.
D.
It is independent of temperature.
Show solution
Solution
Raoult's Law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent.
Correct Answer: A — It is directly proportional to the mole fraction of the solvent.
Learn More →
Q. What happens to the boiling point of a solvent when a non-volatile solute is added?
A.
It decreases
B.
It remains the same
C.
It increases
D.
It becomes zero
Show solution
Solution
The boiling point of a solvent increases when a non-volatile solute is added due to boiling point elevation.
Correct Answer: C — It increases
Learn More →
Q. What happens to the freezing point of a solvent when a non-volatile solute is added?
A.
It increases
B.
It decreases
C.
It remains the same
D.
It fluctuates
Show solution
Solution
The freezing point of a solvent decreases when a non-volatile solute is added, a phenomenon known as freezing point depression.
Correct Answer: B — It decreases
Learn More →
Q. What happens to the vapor pressure of a solution as the concentration of a non-volatile solute increases?
A.
It increases.
B.
It decreases.
C.
It remains constant.
D.
It fluctuates.
Show solution
Solution
As the concentration of a non-volatile solute increases, the vapor pressure of the solution decreases according to Raoult's Law.
Correct Answer: B — It decreases.
Learn More →
Q. What happens to the vapor pressure of a solvent when a non-volatile solute is added?
A.
It increases
B.
It decreases
C.
It remains the same
D.
It fluctuates
Show solution
Solution
The vapor pressure of a solvent decreases when a non-volatile solute is added due to the solute particles occupying space at the surface.
Correct Answer: B — It decreases
Learn More →
Q. What happens to the vapor pressure of a solvent when a volatile solute is added?
A.
It increases.
B.
It decreases.
C.
It remains the same.
D.
It becomes zero.
Show solution
Solution
The addition of a volatile solute decreases the vapor pressure of the solvent due to the presence of solute molecules.
Correct Answer: B — It decreases.
Learn More →
Q. What is Raoult's Law primarily used to describe?
A.
The behavior of ideal gases
B.
The vapor pressure of solutions
C.
The boiling point elevation
D.
The freezing point depression
Show solution
Solution
Raoult's Law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent.
Correct Answer: B — The vapor pressure of solutions
Learn More →
Q. What is Raoult's Law primarily used to determine?
A.
Vapor pressure of a solution
B.
Boiling point elevation
C.
Freezing point depression
D.
Molarity of a solution
Show solution
Solution
Raoult's Law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent.
Correct Answer: A — Vapor pressure of a solution
Learn More →
Q. What is the boiling point elevation of a solution containing 1 mol of NaCl in 1 kg of water? (K_b for water = 0.512 °C kg/mol)
A.
0.512 °C
B.
1.024 °C
C.
1.536 °C
D.
2.048 °C
Show solution
Solution
Boiling point elevation = i * K_b * m = 2 * 0.512 * 1 = 1.024 °C (i = 2 for NaCl)
Correct Answer: B — 1.024 °C
Learn More →
Q. What is the boiling point of a solution containing 0.5 mol of KCl in 1 kg of water? (K_b for water = 0.512 °C kg/mol)
A.
1.024 °C
B.
0.512 °C
C.
1.536 °C
D.
2.048 °C
Show solution
Solution
Boiling point elevation = i * K_b * m = 2 * 0.512 * 0.5 = 0.512 °C; Boiling point = 100 + 0.512 = 100.512 °C
Correct Answer: C — 1.536 °C
Learn More →
Q. What is the concentration in g/L of a solution containing 0.5 moles of KCl in 1.5 L of solution? (Molar mass of KCl = 74.5 g/mol)
A.
24.83 g/L
B.
49.67 g/L
C.
37.25 g/L
D.
50 g/L
Show solution
Solution
Mass of KCl = 0.5 moles × 74.5 g/mol = 37.25 g. Concentration = 37.25 g / 1.5 L = 24.83 g/L.
Correct Answer: B — 49.67 g/L
Learn More →
Q. What is the concentration in molality of a solution made by dissolving 5 moles of solute in 3 kg of solvent?
A.
1.67 m
B.
2 m
C.
1.5 m
D.
2.5 m
Show solution
Solution
Molality (m) = moles of solute / kg of solvent = 5 moles / 3 kg = 1.67 m.
Correct Answer: B — 2 m
Learn More →
Q. What is the concentration in molarity of a solution that contains 0.5 moles of solute in 1.5 liters of solution?
A.
0.33 M
B.
0.5 M
C.
0.75 M
D.
1 M
Show solution
Solution
Molarity (M) = moles of solute / liters of solution = 0.5 moles / 1.5 L = 0.33 M.
Correct Answer: C — 0.75 M
Learn More →
Q. What is the concentration in ppm of a solution containing 1 gram of solute in 1 liter of solution?
A.
1000 ppm
B.
100 ppm
C.
10 ppm
D.
1 ppm
Show solution
Solution
PPM = (mass of solute in grams / volume of solution in liters) * 10^6 = (1 g / 1 L) * 10^6 = 1000 ppm.
Correct Answer: A — 1000 ppm
Learn More →
Q. What is the concentration of a solution if 10 grams of NaCl is dissolved in 500 mL of water? (Molar mass of NaCl = 58.5 g/mol)
A.
0.34 M
B.
0.17 M
C.
0.50 M
D.
0.25 M
Show solution
Solution
Molarity (M) = moles of solute / liters of solution = (10 g / 58.5 g/mol) / 0.5 L = 0.34 M.
Correct Answer: A — 0.34 M
Learn More →
Q. What is the effect of a non-volatile solute on the boiling point of a solvent?
A.
It decreases the boiling point
B.
It increases the boiling point
C.
It has no effect
D.
It changes the boiling point unpredictably
Show solution
Solution
The addition of a non-volatile solute raises the boiling point of the solvent, a phenomenon known as boiling point elevation.
Correct Answer: B — It increases the boiling point
Learn More →
Q. What is the effect of adding a non-volatile solute to a solvent on the vapor pressure of the solvent?
A.
It increases the vapor pressure.
B.
It decreases the vapor pressure.
C.
It has no effect on the vapor pressure.
D.
It doubles the vapor pressure.
Show solution
Solution
Adding a non-volatile solute decreases the vapor pressure of the solvent due to the reduction in the mole fraction of the solvent.
Correct Answer: B — It decreases the vapor pressure.
Learn More →
Q. What is the effect of increasing temperature on the vapor pressure of a solution?
A.
It decreases the vapor pressure.
B.
It increases the vapor pressure.
C.
It has no effect.
D.
It causes the vapor pressure to become zero.
Show solution
Solution
Increasing temperature generally increases the vapor pressure of a solution due to increased kinetic energy of the molecules.
Correct Answer: B — It increases the vapor pressure.
Learn More →
Showing 91 to 120 of 247 (9 Pages)