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Q. If 10^(2x) = 100, what is the value of x?

A. 0
B. 0.5
C. 1
D. 2

Solution

100 = 10^2, so 2x = 2, hence x = 1.

Correct Answer: B — 0.5

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Q. If 10^x = 0.01, what is the value of x?

A. -2
B. -1
C. 0
D. 1

Solution

Since 0.01 = 10^(-2), we have x = -2.

Correct Answer: A — -2

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Q. If 15 grams of HCl is dissolved in 500 mL of solution, what is the molarity of the solution? (Molar mass of HCl = 36.5 g/mol)

A. 0.82 M
B. 1.0 M
C. 0.5 M
D. 1.5 M

Solution

Moles of HCl = 15 g / 36.5 g/mol = 0.41096 moles. Molarity = 0.41096 moles / 0.5 L = 0.82192 M.

Correct Answer: A — 0.82 M

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Q. If 15 grams of sugar is dissolved in 250 mL of solution, what is the molarity of the solution? (Molar mass of sugar = 180 g/mol)

A. 0.33 M
B. 0.5 M
C. 0.25 M
D. 0.75 M

Solution

Moles of sugar = 15 g / 180 g/mol = 0.0833 moles. Molarity = 0.0833 moles / 0.25 L = 0.333 M.

Correct Answer: A — 0.33 M

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Q. If 15 grams of sugar is dissolved in 250 mL of water, what is the molarity of the solution? (Molar mass of sugar = 180 g/mol)

A. 0.33 M
B. 0.5 M
C. 0.25 M
D. 0.75 M

Solution

Moles of sugar = 15 g / 180 g/mol = 0.0833 moles. Molarity = 0.0833 moles / 0.25 L = 0.333 M.

Correct Answer: A — 0.33 M

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Q. If 2 moles of a gas occupy 44.8 L at STP, what is the molar volume of the gas?

A. 22.4 L
B. 44.8 L
C. 11.2 L
D. 33.6 L

Solution

At STP, 1 mole of gas occupies 22.4 L. Therefore, the molar volume of the gas is 22.4 L.

Correct Answer: A — 22.4 L

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Q. If 2 moles of an ideal gas at 300 K occupy a volume of 10 L, what is the pressure of the gas? (Use R = 0.0821 L·atm/(K·mol))

A. 0.5 atm
B. 1.0 atm
C. 2.0 atm
D. 3.0 atm

Solution

Using the Ideal Gas Law, P = nRT/V = (2 moles * 0.0821 L·atm/(K·mol) * 300 K) / 10 L = 4.926 atm.

Correct Answer: B — 1.0 atm

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Q. If 2 moles of glucose are dissolved in 1 liter of water, what is the molarity of the solution?

A. 1 M
B. 2 M
C. 0.5 M
D. 3 M

Solution

Molarity = moles of solute / liters of solution = 2 moles / 1 L = 2 M.

Correct Answer: B — 2 M

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Q. If 2 moles of KCl are dissolved in 1 liter of solution, what is the molarity of the solution?

A. 1 M
B. 2 M
C. 0.5 M
D. 3 M

Solution

Molarity (M) = moles of solute / liters of solution = 2 moles / 1 L = 2 M.

Correct Answer: B — 2 M

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Q. If 2 moles of NaCl are dissolved in 1 kg of water, what is the van 't Hoff factor (i)?

A. 1
B. 2
C. 3
D. 4

Solution

NaCl dissociates into 2 ions (Na⁺ and Cl⁻), so the van 't Hoff factor (i) is 2.

Correct Answer: C — 3

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Q. If 20 grams of glucose (C6H12O6) is dissolved in 200 mL of solution, what is the mass percent concentration? (Molar mass of glucose = 180 g/mol)

A. 10%
B. 5%
C. 20%
D. 15%

Solution

Mass percent = (mass of solute / total mass of solution) x 100 = (20 g / (20 g + 200 g)) x 100 = 10%.

Correct Answer: A — 10%

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Q. If 200 g of ice at 0°C is added to 100 g of water at 80°C, what will be the final temperature of the mixture? (Latent heat of fusion of ice = 334 J/g)

A. 0°C
B. 20°C
C. 40°C
D. 60°C

Solution

Heat lost by water = Heat gained by ice. 100g * 80°C = 200g * 334 J/g + 200g * (Tf - 0°C). Solving gives Tf = 20°C.

Correct Answer: B — 20°C

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Q. If 2x + 3y = 12 and x + 2y = 10, what is the value of x?

A. 2
B. 3
C. 4
D. 5

Solution

From the second equation, x = 10 - 2y. Substituting into the first gives 2(10 - 2y) + 3y = 12, solving gives y = 2, x = 6.

Correct Answer: C — 4

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Q. If 2^(x+1) = 16, what is the value of x?

A. 2
B. 3
C. 4
D. 5

Solution

16 = 2^4 => x + 1 = 4 => x = 3

Correct Answer: B — 3

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Q. If 3 moles of a gas occupy 60 liters at STP, what is the molar volume of the gas?

A. 20 L
B. 30 L
C. 40 L
D. 60 L

Solution

Molar volume = total volume / number of moles = 60 L / 3 moles = 20 L/mole.

Correct Answer: B — 30 L

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Q. If 3 moles of a gas occupy 60 liters, what is the volume occupied by 1 mole of the gas at the same conditions?

A. 20 L
B. 30 L
C. 15 L
D. 10 L

Solution

Volume per mole = total volume / number of moles = 60 L / 3 moles = 20 L/mole.

Correct Answer: A — 20 L

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Q. If 300 g of water at 25°C is mixed with 200 g of water at 75°C, what is the final temperature? (Specific heat of water = 4.2 J/g°C)

A. 40°C
B. 50°C
C. 60°C
D. 70°C

Solution

Using m1*T1 + m2*T2 = (m1 + m2)*Tf, we find Tf = (300*25 + 200*75) / (300 + 200) = 50°C.

Correct Answer: B — 50°C

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Q. If 3^(2x) = 81, what is the value of x?

A. 2
B. 3
C. 4
D. 1

Solution

Since 81 = 3^4, we have 3^(2x) = 3^4, thus 2x = 4, giving x = 2.

Correct Answer: A — 2

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Q. If 4 moles of aluminum react with 3 moles of oxygen, how many moles of aluminum oxide are formed?

A. 2 moles
B. 3 moles
C. 4 moles
D. 6 moles

Solution

The balanced equation is 4Al + 3O2 → 2Al2O3, which shows that 4 moles of Al produce 2 moles of Al2O3.

Correct Answer: A — 2 moles

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Q. If 4 moles of solute are dissolved in 2 kg of solvent, what is the molality of the solution?

A. 2 m
B. 4 m
C. 1 m
D. 0.5 m

Solution

Molality (m) = moles of solute / kg of solvent = 4 moles / 2 kg = 2 m.

Correct Answer: A — 2 m

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Q. If 4^x = 64, what is the value of x?

A. 2
B. 3
C. 4
D. 5

Solution

Since 64 = 4^3, we have x = 3.

Correct Answer: B — 3

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Q. If 5 g of CaCO3 decomposes completely, how many grams of CaO are produced?

A. 2 g
B. 3 g
C. 4 g
D. 5 g

Solution

CaCO3 → CaO + CO2. Molar mass of CaCO3 = 100 g, CaO = 56 g. 5 g of CaCO3 produces (5 g * 56 g) / 100 g = 2.8 g of CaO.

Correct Answer: C — 4 g

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Q. If 5 moles of KCl are dissolved in 1 kg of water, what is the molality of the solution?

A. 5 m
B. 2.5 m
C. 10 m
D. 1 m

Solution

Molality (m) = moles of solute / kg of solvent = 5 moles / 1 kg = 5 m.

Correct Answer: A — 5 m

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Q. If 5 moles of KCl are dissolved in 3 kg of water, what is the molality of the solution?

A. 1.67 m
B. 2.5 m
C. 1.25 m
D. 0.5 m

Solution

Molality (m) = moles of solute / kg of solvent = 5 moles / 3 kg = 1.67 m.

Correct Answer: A — 1.67 m

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Q. If 5 moles of NaCl are dissolved in water, how many moles of Na+ ions are present?

A. 5 moles
B. 10 moles
C. 2.5 moles
D. 0 moles

Solution

Each mole of NaCl dissociates into 1 mole of Na+ ions. Therefore, 5 moles of NaCl will produce 5 moles of Na+ ions.

Correct Answer: A — 5 moles

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Q. If 50 g of KCl is dissolved in 250 mL of solution, what is the molarity? (Molar mass of KCl = 74.5 g/mol)

A. 2.68 M
B. 1.34 M
C. 0.67 M
D. 0.25 M

Solution

Moles of KCl = 50 g / 74.5 g/mol = 0.672 moles. Molarity = 0.672 moles / 0.25 L = 2.688 M.

Correct Answer: B — 1.34 M

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Q. If 50 grams of a solute is dissolved in 200 mL of solution, what is the mass/volume percent concentration?

A. 25%
B. 20%
C. 15%
D. 10%

Solution

Mass/volume percent = (mass of solute / volume of solution) * 100 = (50 g / 200 mL) * 100 = 25%.

Correct Answer: A — 25%

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Q. If 50 grams of NaCl is dissolved in 1 liter of solution, what is the molarity? (Molar mass of NaCl = 58.5 g/mol)

A. 0.85 M
B. 1.0 M
C. 1.5 M
D. 2.0 M

Solution

Moles of NaCl = 50 g / 58.5 g/mol = 0.854 moles. Molarity = 0.854 moles / 1 L = 0.854 M.

Correct Answer: B — 1.0 M

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Q. If 50 grams of NaOH is dissolved in 1 liter of solution, what is the molarity? (Molar mass of NaOH = 40 g/mol)

A. 1.25 M
B. 2.5 M
C. 0.5 M
D. 1 M

Solution

Moles of NaOH = 50 g / 40 g/mol = 1.25 moles. Molarity = 1.25 moles / 1 L = 1.25 M.

Correct Answer: B — 2.5 M

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Q. If 50 mL of 0.1 M HCl is mixed with 50 mL of 0.1 M NaOH, what is the resulting pH?

A. 7
B. 1
C. 14
D. 0

Solution

HCl and NaOH neutralize each other, resulting in a neutral solution with pH = 7.

Correct Answer: A — 7

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