Curriculum
Login

Curriculum

Chemistry — Second Secondary

Chemistry — Second Secondary

0/75

Chemistry — Second Secondary 2026/2027

0/47
Quiz

Question bank: Chapter 1 — Chemical Calculation

Submit quiz
Once you submit, you will no longer be able to change your answers. Are you sure you want to submit the quiz?
Cancel Submit
  • Questions count: 40
Start Quiz
1.
In the International System of Units, the amount of a substance is measured in
gram
mole
litre
kelvin
2.
The number of particles in one mole of any substance is
6.02 × 1022
22.4 × 1023
6.02 × 1023
6.02 × 1024
3.
The number of hydrogen atoms in 1 mol of H₂ molecules is
6.02 × 1023
3.01 × 1023
1.806 × 1024
12.04 × 1023
4.
The molar mass of sodium hydroxide NaOH is
40 g/mol
39 g/mol
24 g/mol
56 g/mol
5.
The molar mass of hydrated copper(II) sulphate CuSO₄·5H₂O is
159.5 g/mol
177.5 g/mol
249.5 g/mol
321.5 g/mol
6.
The number of moles in 36 g of water is
0.5 mol
1 mol
2 mol
4 mol
7.
The mass of 0.25 mol of carbon dioxide is
11 g
22 g
44 g
5.5 g
8.
The number of molecules in 0.1 mol of any molecular substance is
6.02 × 1022
6.02 × 1024
6.02 × 1021
0.1 × 1024
9.
Which sample contains the greatest number of atoms?
1 mol of H₂O
1 mol of CO₂
1 mol of NH₃
1 mol of CH₄
10.
The number of ions produced when 0.1 mol of CaCl₂ dissolves completely in water is
1.806 × 1023
6.02 × 1022
1.204 × 1023
3.01 × 1023
11.
One mole of any gas occupies at STP a volume of
22.4 mL
24 L
22.4 L
1 L
12.
The standard conditions STP are
25 °C and 1 atm
0 °C and 1 atm
0 °C and 2 atm
273 °C and 1 atm
13.
The volume of 2 mol of nitrogen gas at rtp is
22.4 L
44.8 L
24 L
48 L
14.
Equal volumes of different gases at the same temperature and pressure contain equal numbers of
atoms
molecules
grams
electrons only
15.
The volume at STP of 3.2 g of oxygen gas is
2.24 L
4.48 L
22.4 L
0.224 L
16.
The number of moles in 5.6 L of a gas at STP is
0.25
0.5
1
2.5
17.
A gas has a mass of 3.5 g and a volume of 2.8 L at STP. Its molar mass is
14 g/mol
28 g/mol
32 g/mol
44 g/mol
18.
The molar volume at room temperature and pressure is larger than at STP because
the gas becomes heavier
the gas expands at the higher temperature
the pressure is lower than 1 atm
the number of molecules increases
19.
In 2H₂ + O₂ → 2H₂O (gases, same T and P), the volume of oxygen required to react with 10 L of hydrogen is
20 L
10 L
5 L
2.5 L
20.
2Na + 2H₂O → 2NaOH + H₂. The mass of sodium that releases 1.12 L of hydrogen at STP is
1.15 g
2.3 g
4.6 g
0.23 g
21.
CaCO₃ → CaO + CO₂. Heating 10 g of CaCO₃ gives CO₂ of mass
4.4 g
2.2 g
10 g
44 g
22.
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O. The number of moles of oxygen needed to burn 2 mol of ethane is
2
3.5
7
14
23.
Which statement about a balanced equation is correct?
the number of moles of reactants always equals that of products
the total mass of reactants equals the total mass of products
the volume of liquids is conserved
the coefficients give masses in grams
24.
The limiting reactant is the reactant that
is present in the largest mass
is completely consumed first
is a gas
has the largest molar mass
25.
To identify the limiting reactant we compare, for each reactant,
the given mass
the molar mass
the given moles divided by its coefficient
the coefficient only
26.
N₂ + 3H₂ → 2NH₃. A mixture of 2 mol N₂ and 3 mol H₂ reacts. The limiting reactant is
N₂
H₂
NH₃
neither
27.
N₂ + 3H₂ → 2NH₃. From 1 mol of N₂ and 6 mol of H₂ the moles of NH₃ formed are
1
2
4
6
28.
2Mg + O₂ → 2MgO. 0.4 mol of Mg is heated with 0.1 mol of O₂. The moles of MgO formed are
0.1
0.2
0.4
0.5
29.
The empirical formula of glucose C₆H₁₂O₆ is
CHO
CH₂O
C₂H₄O₂
C₃H₆O₃
30.
A compound has C : H atom ratio of 1 : 1.5. Its empirical formula is
CH₂
C₂H₃
C₃H₂
CH₃
31.
A compound has the empirical formula CH₂O and molar mass 60 g/mol. Its molecular formula is
CH₂O
C₂H₄O₂
C₃H₆O₃
C₄H₈O₄
32.
Which pair of compounds has the same empirical formula?
CO and CO₂
C₂H₄ and C₃H₆
H₂O and H₂O₂
NO and NO₂
33.
A formula that shows how the atoms are bonded to each other is the
empirical formula
molecular formula
structural formula
formula mass
34.
When a hydrocarbon burns completely, the carbon of the sample is converted into
CO
CO₂
C
H₂CO₃
35.
The mass of carbon contained in 22 g of CO₂ is
12 g
6 g
3 g
22 g
36.
The molarity of a solution containing 0.5 mol of solute in 250 mL is
0.5 M
1 M
2 M
4 M
37.
The mass of NaOH in 100 mL of a 0.5 M solution is
1 g
2 g
4 g
20 g
38.
The concentration of chloride ions in 0.1 M MgCl₂ solution is
0.05 M
0.1 M
0.2 M
0.3 M
39.
50 mL of 2 M HCl is diluted with water to 200 mL. The new molarity is
0.25 M
0.5 M
1 M
8 M
40.
The volume of water that must be added to 100 mL of 1 M solution to make it 0.25 M is
100 mL
300 mL
400 mL
25 mL
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40