Class: C2 Syllabus 5070 (2025-2027)
Chemistry
Chapters: Stoichiometry-I Paper-I: Multiple choice
Name: Class:
1. 10 cm3 of hydrogen gas is mixed with x cm3 of chlorine gas. The equation for the reaction is shown.
H2 (g) + C𝑙2(g) → 2HC𝑙(g)
All the hydrogen reacts. The total volume of gas at the end of the reaction is 40 cm3.
All measurements are at room temperature and pressure. What is the value of x?
A 10 cm3 B 20 cm3 C 30 cm3 D 40 cm3
2. 100 cm3 of aqueous potassium hydroxide with a concentration of 1.00 mol / dm3 reacts with excess dilute
sulfuric acid.
2KOH (aq) + H2 SO4(aq) → K 2 SO4(aq) + 2H2 O(l)
3.48 g of pure anhydrous potassium sulfate is produced. What is the percentage yield of potassium sulfate?
A 5% B 10% C 20% D 40%
3. Which compound has the highest relative formula mass, Mr?
[Ar: K, 39; N, 14; O, 16; Ca, 40; C, 12; Li, 7; S, 32; Mg, 24; Cl, 35.5]
A calcium carbonate
B lithium sulfate
C magnesium chloride
D potassium nitrate
4. 100 cm3 of ethene(C2H4) is completely combusted in 400 cm3 of oxygen.
C2 H4 (g) + 2O2(g) → CO2(g) + 2H2 O(l)
What is the final volume of gas in the mixture measured at r.t.p.?
A 200 cm3 B 250 cm3 C 300 cm3 D 500 cm3
5. The formula of hydrated sodium carbonate is Na2CO3•10H2O. What is %age by mass of oxygen in it?
A 16.8 B 22.4 C 55.9 D 72.7
6. Which contains the greatest mass of oxygen?
A 0.1 mol of aluminium nitrate, Al(NO3)3
B 0.2 mol of potassium sulfate, K2SO4
C 0.3 mol of sodium nitrate, NaNO3
D 0.4 mol of magnesium carbonate, MgCO3
7. Compound X has a composition by mass of 63.6 % nitrogen and 36.4 % oxygen. What is empirical formula?
A N2O B NO C NO2 D N2O4
8. Magnesium will react with aqueous copper(II) sulfate to form copper and aqueous magnesium sulfate. What
is the correct equation for this reaction?
9. A sample of magnesium hydroxide has a mass of 5.63 g. How many moles of magnesium hydroxide are
present?
A 0.0617 B 0.0798 C 0.0971 D 0.154
10. Which sample contains the greatest number of atoms?
A 10 g of water B 10 dm3 of carbon dioxide
3
C 10 dm of oxygen D 10 g of Hydrogen chloride
11. The empirical formula of compound X is CH2 and the relative molecular mass, Mr, of X is 28. What is the
molecular formula of X?
A CH2 B C2H4 C C5H10 D CnH2n
12. The relative formula masses of four compounds are given. A student has a 1.0 g sample of each compound.
Which sample contains the highest number of moles of oxygen atoms?
compound relative formula mass
A Al2O3 102
B CuO 80
C HNO3 63
D H2SO4 98
13. The relative atomic mass of chlorine is 35.5. What is the mass of 2.0 mol of chlorine gas?
A 17.75 g B 35.5 g C 71 g D 142 g
Chemistry
Chapters: Stoichiometry-I Paper-I: Multiple choice
Name: Class:
1. 10 cm3 of hydrogen gas is mixed with x cm3 of chlorine gas. The equation for the reaction is shown.
H2 (g) + C𝑙2(g) → 2HC𝑙(g)
All the hydrogen reacts. The total volume of gas at the end of the reaction is 40 cm3.
All measurements are at room temperature and pressure. What is the value of x?
A 10 cm3 B 20 cm3 C 30 cm3 D 40 cm3
2. 100 cm3 of aqueous potassium hydroxide with a concentration of 1.00 mol / dm3 reacts with excess dilute
sulfuric acid.
2KOH (aq) + H2 SO4(aq) → K 2 SO4(aq) + 2H2 O(l)
3.48 g of pure anhydrous potassium sulfate is produced. What is the percentage yield of potassium sulfate?
A 5% B 10% C 20% D 40%
3. Which compound has the highest relative formula mass, Mr?
[Ar: K, 39; N, 14; O, 16; Ca, 40; C, 12; Li, 7; S, 32; Mg, 24; Cl, 35.5]
A calcium carbonate
B lithium sulfate
C magnesium chloride
D potassium nitrate
4. 100 cm3 of ethene(C2H4) is completely combusted in 400 cm3 of oxygen.
C2 H4 (g) + 2O2(g) → CO2(g) + 2H2 O(l)
What is the final volume of gas in the mixture measured at r.t.p.?
A 200 cm3 B 250 cm3 C 300 cm3 D 500 cm3
5. The formula of hydrated sodium carbonate is Na2CO3•10H2O. What is %age by mass of oxygen in it?
A 16.8 B 22.4 C 55.9 D 72.7
6. Which contains the greatest mass of oxygen?
A 0.1 mol of aluminium nitrate, Al(NO3)3
B 0.2 mol of potassium sulfate, K2SO4
C 0.3 mol of sodium nitrate, NaNO3
D 0.4 mol of magnesium carbonate, MgCO3
7. Compound X has a composition by mass of 63.6 % nitrogen and 36.4 % oxygen. What is empirical formula?
A N2O B NO C NO2 D N2O4
8. Magnesium will react with aqueous copper(II) sulfate to form copper and aqueous magnesium sulfate. What
is the correct equation for this reaction?
9. A sample of magnesium hydroxide has a mass of 5.63 g. How many moles of magnesium hydroxide are
present?
A 0.0617 B 0.0798 C 0.0971 D 0.154
10. Which sample contains the greatest number of atoms?
A 10 g of water B 10 dm3 of carbon dioxide
3
C 10 dm of oxygen D 10 g of Hydrogen chloride
11. The empirical formula of compound X is CH2 and the relative molecular mass, Mr, of X is 28. What is the
molecular formula of X?
A CH2 B C2H4 C C5H10 D CnH2n
12. The relative formula masses of four compounds are given. A student has a 1.0 g sample of each compound.
Which sample contains the highest number of moles of oxygen atoms?
compound relative formula mass
A Al2O3 102
B CuO 80
C HNO3 63
D H2SO4 98
13. The relative atomic mass of chlorine is 35.5. What is the mass of 2.0 mol of chlorine gas?
A 17.75 g B 35.5 g C 71 g D 142 g
