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 |
1. Fe3O2
2. Fe2O2
3. Fe2O3
4. Fe3O4
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
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
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
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
If the mass of air per unit area at sea level is 1034 g cm–2, pressure in pascal will be:
1. 1.01332 × 105 Pa
2. 1.01332 × 106 Pa
3. 1.01332 × 107 Pa
4. 1.01332 × 108 Pa
The SI unit of mass is:
1. Kilogram (kg)
2. Gram (g)
3. Pascal (Pa)
4. Kilometres (km)
A significant figure is defined as :
| 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. |
The chloroform contamination level in water is 15 ppm (by mass of chloroform). Calculate the molality of chloroform in this water sample, which represents the number of moles of chloroform dissolved per kilogram of pure water solvent:
| 1. | 3.25 × 10-4
|
2. | 1.5 × 10-3
|
| 3. | 7.5 × 10-3
|
4. | 1.25 × 10-4 |