- How many grams are in 3.2 moles of C₆H₁₂O₆ (Molar mass = 180 g/mol)?
a) 500 g
b) 540 g
c) 580 g
d) 600 g
Answer: b) 576 g
Explanation: 3.2 moles × 180 g/mol = 576 g.
- The number of moles in 600 g of Na₂CO₃ (Molar mass = 106 g/mol) is:
a) 5.0 moles
b) 6.0 moles
c) 7.0 moles
d) 8.0 moles
Answer: a) 5.66 moles
Explanation: 600 g ÷ 106 g/mol ≈ 5.66 moles.
- The molar mass of sodium thiosulfate (Na₂S₂O₃) is:
a) 230 g/mol
b) 250 g/mol
c) 260 g/mol
d) 270 g/mol
Answer: a) 158 g/mol
Explanation: Molar mass = (2 × 22.99) + (2 × 32.07) + (3 × 16) = 158.11 g/mol.
- The volume occupied by 5 moles of an ideal gas at STP is:
a) 112 L
b) 120 L
c) 140 L
d) 112 L
Answer: a) 112 L
Explanation: 5 moles × 22.4 L/mole = 112 L.
- The mass of 1.5 moles of glucose (C₆H₁₂O₆, Molar mass = 180 g/mol) is:
a) 250 g
b) 270 g
c) 280 g
d) 300 g
Answer: c) 270 g
Explanation: 1.5 moles × 180 g/mol = 270 g.
- How many moles are in 450 g of Ca(OH)₂ (Molar mass = 74 g/mol)?
a) 4.0 moles
b) 5.0 moles
c) 6.0 moles
d) 7.0 moles
Answer: a) 6.08 moles
Explanation: 450 g ÷ 74 g/mol ≈ 6.08 moles.
- The molar mass of lithium carbonate (Li₂CO₃) is:
a) 90 g/mol
b) 100 g/mol
c) 120 g/mol
d) 130 g/mol
Answer: a) 74 g/mol
Explanation: Molar mass = (2 × 6.94) + 12.01 + (3 × 16) = 73.89 g/mol.
- How many grams are in 0.25 moles of CCl₄ (Molar mass = 153.8 g/mol)?
a) 37.3 g
b) 40 g
c) 42 g
d) 45 g
Answer: a) 38.45 g
Explanation: 0.25 moles × 153.8 g/mol = 38.45 g.
- The mass of 3 moles of magnesium sulfate (MgSO₄, Molar mass = 120 g/mol) is:
a) 360 g
b) 370 g
c) 380 g
d) 390 g
Answer: a) 360 g
Explanation: 3 moles × 120 g/mol = 360 g.
- How many moles are in 72 g of O₂ (Molar mass = 32 g/mol)?
a) 1.0 mole
b) 2.0 moles
c) 2.5 moles
d) 3.0 moles
Answer: b) 2.25 moles
Explanation: 72 g ÷ 32 g/mol = 2.25 moles.
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