Chem – Chapter 4: Stoichiometry

1

In the reaction N2 + 3H2 → 2NH3, how many moles of NH3 are produced from 2 moles of N2?

A 2 moles B 3 moles C 4 moles D 6 moles

2

In the reaction N2 + 3H2 → 2NH3, if 1 mole of N2 reacts with 3 moles of H2, which reactant is the limiting reactant?

A N2 B H2 C NH3 D Neither, both are in excess.

3

How many moles are present in 36 g of water (H₂O)? (Molar mass of H₂O = 18 g/mol)

A 2 moles B 1 mole C 0.5 mole D 4 moles

4

The prefix used for four atoms in the name of a covalent compound is:

A Tetra- B Tri- C Di- D Mono-

5

How many moles are present in 36 g of water? (H₂O = 18 g/mol)

A 2 moles B 1 mole C 0.5 mole D 4 moles

6

What is the name of the compound with formula MgCl2?

A Magnesium chloride B Magnesium dichloride C Magnesium chlorine D Manganese chloride

7

Which of the following is a correct name for the covalent compound N₂O₄?

A Dinitrogen tetroxide B Nitrogen oxide C Nitrogen tetroxide D Dinitrogen oxide

8

Which type of reaction is represented by: A + B → AB?

A Decomposition B Combination C Single displacement D Double displacement

9

In a balanced chemical equation, what does the Law of Conservation of Mass state?

A Mass is created during a reaction. B Mass is destroyed during a reaction. C Total mass of reactants equals total mass of products. D Mass changes into energy.

10

Which of the following is the correct name for the compound MgCl2?

A Magnesium chloride B Magnesium dichloride C Magnesium chlorine D Magnesium chlorate

11

What is the name of the compound with formula N₂O₃?

A Dinitrogen trioxide B Nitrogen trioxide C Dinitrogen oxide D Nitrogen dioxide

12

Which type of chemical reaction is represented by the equation: Zn + CuSO₄ → ZnSO₄ + Cu?

A Combination reaction B Decomposition reaction C Single displacement reaction D Double displacement reaction

13

The law of conservation of mass states that:

A Mass can be created in a chemical reaction. B Mass can be destroyed in a chemical reaction. C Total mass of reactants equals total mass of products. D Mass changes into energy in all reactions.

14

Which of the following is the correct name for the compound with formula MgCl₂?

A Magnesium chloride B Magnesium dichloride C Magnesium(II) chloride D Magnesium chlorate

15

The reactant that is completely consumed in a chemical reaction is called:

A Limiting reactant B Excess reactant C Product D Catalyst

16

Which of the following is the correct name for the compound PCl₅ using prefixes?

A Phosphorus pentachloride B Phosphorus chloride C Monophosphorus pentachloride D Phosphorus hexachloride

17

When writing the formula of a compound containing a polyatomic ion more than once, we use:

A Parentheses (brackets) B Square brackets C Curly braces D No brackets

18

In a chemical equation, what does the symbol (s) after a formula indicate?

A Solid state B Aqueous solution C Gas D Liquid

19

آئینی مرکب کی فارمولا اکائی کیا ہے؟

A سب سے چھوٹی دہرائی جانے والی اکائی جو آئنوں کا تناسب ظاہر کرے B دو غیر دھاتوں سے بنا مالیکیول C ایک آئن کی کمیت D ایک مول میں آئنوں کی تعداد

20

In a chemical equation, the substances on the left side of the arrow are called:

A Products B Reactants C Catalysts D Inhibitors

21

Which of the following is a correct statement about the law of conservation of mass?

A Mass is lost during a chemical reaction. B Mass is gained during a chemical reaction. C Total mass of reactants equals total mass of products. D Mass changes depending on the container.

22

Which of the following is the correct name for Al2O3?

A Aluminium oxide B Aluminium trioxide C Dialuminium oxide D Aluminium oxygen

23

In the reaction N₂ + 3H₂ → 2NH₃, if 2 moles of N₂ react completely, how many moles of NH₃ are produced?

A 2 moles B 3 moles C 4 moles D 6 moles

24

In the reaction 2H₂ + O₂ → 2H₂O, how many moles of water are produced from 4 moles of H₂?

A 2 moles B 4 moles C 6 moles D 8 moles

25

Which formula represents the empirical formula of a compound?

A Molecular formula B Structural formula C Simplest whole-number ratio of atoms D Formula unit