The amount of CO2 that can be produced when 2 moles of carbon are burnt in 16 g of dioxygen is:

1. 22 g 2. 44 g
3. 0.5 g 4. 11 g

Subtopic:  Limiting Reagent | Equation Based Problem |
 74%
Level 2: 60%+
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The amount of copper (in grams) that can be obtained from 100 g of copper sulphate (CuSO4) is:

1. 54.00   2. 39.81
3. 63.50   4. 159.50
Subtopic:  Moles, Atoms & Electrons |
 72%
Level 2: 60%+
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An oxide of iron contains 69.9% iron and 30.1% oxygen by mass. Which of the following is its empirical formula?

1. Fe3O2

2. Fe2O3

3. Fe2O2

4. Fe3O4

Subtopic:  Empirical & Molecular Formula |
Level 4: Below 35%
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The average atomic mass of chlorine using the following data would be:

Isotope

% Natural

Abundance

Molar Mass

35Cl  75.77 34.9689
37Cl  24.23 36.9659


1. 38.4527 u

2. 37.4527 u

3. 36.4527 u

4. 35.4527 u

Subtopic:  Empirical & Molecular Formula |
 79%
Level 2: 60%+
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Determine the number of moles of hydrogen atoms present in 3 moles of ethane (C2H6):

1. 18.069 × 1023

2. 1.8 × 1023

3. 18

4. 6 × 1023

Subtopic:  Moles, Atoms & Electrons |
 65%
Level 2: 60%+
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Find the concentration of sugar, C₁₂H₂₂O₁₁, in mol L⁻¹ when 20 g of sugar is dissolved in enough water to make 2 L of solution.

1. 0.29 mol/L

2. 0.029 mol/L

3. 0.35 mol/L

4. 0.032 mol/L

Subtopic:  Concentration Based Problem |
 78%
Level 2: 60%+
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How much volume of methanol is needed to prepare 2.5 L of a 0.25 M solution, if the density of methanol is 0.793 kg/L?

1. 22.25 mL
2. 24.78 mL

3. 25.22 mL 

4. 28.52 mL

Subtopic:  Concentration Based Problem |
 62%
Level 2: 60%+
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If the mass of air above a unit area at sea level is 1034 g cm⁻², what is the corresponding atmospheric pressure in pascal?

1. 1.01332 × 105 Pa

2. 1.01332 × 106 Pa

3. 1.01332 × 107 Pa

4. 1.01332 × 108 Pa

Subtopic:  Introduction |
 67%
Level 2: 60%+
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Which of the following is the SI unit of mass?

1. Kilogram (kg)

2. Gram (g)

3. Pascal (Pa)

4. Kilometres (km)

Subtopic:  Introduction |
 88%
Level 1: 80%+
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Which of the following correctly defines significant figures ?

1. The total number of digits in a number, including the last digit that represents the uncertainty of the result. 
2. The total number of digits in a number, excluding the last digit, which represents the uncertainty of the result.
3. The total number of digits in a number including the last digit that represents the certainty of the result. 
4. The total number of last digits that represents the uncertainty of the result. 

Subtopic:  Introduction |
 51%
Level 3: 35%-60%
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