Chemistry Comprehensive Practice Test 6

Questions

100

Marks

Sections

100%

Auto-Graded

Section	Questions	Marks Each	Total
A — Multiple Choice	15	2	30
B — True / False	10	2	20
C — Fill in the Blank	10	2	20
D — Column Matching	5 sub-questions	2	10
E — Short Answer	5	4	20
Total	45	—	100

Source scope: This paper covers the 12 Chemistry articles currently in the EDUSAMBAM master library: Acids, Bases and Salts: The Chemistry of Sour, Bitter, and Neutral; Atoms and the Periodic Table: The Building Blocks of Everything; Chemical Bonding: How Atoms Connect to Form Everything; Chemical Reactions and Equations: The Language of Change; Chemistry in Everyday Life: The Science Hiding in Plain Sight; Electrochemistry: Where Chemistry Meets Electricity; Chemistry of Metals and Non-Metals: A Tale of Two Families; Mixtures and Solutions: How Substances Combine Without Reacting; The Mole and Chemical Calculations: Counting the Uncountable; Organic Chemistry Basics: The Chemistry of Carbon; States of Matter and Changes: Why Substances Transform; What is Chemistry? The Science of Matter and Change. Questions progress from basic concepts to intermediate application and advanced reasoning.

Section A — Multiple Choice

30 marks

15 questions · 2 marks each. Select the best answer.

1.At constant pressure, heating a liquid generally causes its particles to:Basic2 pts

A. Lose all motion

B. Gain kinetic energy

C. Become neutrons

D. Stop colliding

2.If 2 mol of H₂ react completely with O₂ according to 2H₂ + O₂ → 2H₂O, how many moles of H₂O form?Intermediate2 pts

A. 1

B. 2

C. 3

D. 4

3.Which statement best explains why catalysts speed many reactions?Advanced2 pts

A. They permanently increase product energy

B. They provide an alternative pathway with lower activation energy

C. They change the equilibrium constant in every reaction

D. They are consumed as reactants

4.In a galvanic cell, chemical energy is primarily converted into:Intermediate2 pts

A. Electrical energy

B. Sound energy

C. Nuclear energy

D. Gravitational energy

5.Which pair is most likely to form a covalent molecular compound?Intermediate2 pts

A. Sodium and chlorine

B. Magnesium and oxygen

C. Carbon and oxygen

D. Potassium and bromine

6.Which particle has a positive charge?Basic2 pts

A. Electron

B. Proton

C. Neutron

D. Photon

7.The atomic number of an element equals the number of:Basic2 pts

A. Neutrons only

B. Protons only

C. Protons plus neutrons

D. Electrons plus neutrons

8.Which type of bond is formed mainly by transfer of electrons?Basic2 pts

A. Ionic

B. Covalent

C. Metallic

D. Hydrogen

9.A balanced chemical equation must have the same number of each type of:Basic2 pts

A. Molecule

B. Compound

C. Atom

D. Reaction

10.Which of the following is a mixture?Basic2 pts

A. Oxygen

B. Distilled water

C. Air

D. Sodium chloride crystal

11.The mass number of an atom is the total number of:Basic2 pts

A. Protons and neutrons

B. Protons and electrons

C. Electrons and neutrons

D. Valence electrons only

12.Which molecule is non-polar overall because of its symmetrical linear shape?Advanced2 pts

A. CO₂

B. H₂O

C. NH₃

D. HCl

13.Why is a chemical equation balanced?Intermediate2 pts

A. To obey conservation of atoms

B. To make products heavier

C. To increase reaction speed

D. To make all coefficients equal

14.Which metal is commonly protected by a thin oxide layer that prevents further corrosion?Intermediate2 pts

A. Aluminium

B. Sodium

C. Potassium

D. Calcium

15.In electrochemistry, the salt bridge primarily helps maintain:Advanced2 pts

A. Electrical neutrality and ion flow

B. Higher temperature only

C. Zero ion movement

D. The mass of electrodes

Section B — True / False

20 marks

10 questions · 2 marks each. Choose True or False.

16.Bases can neutralize acids.Basic2 pts

True

False

17.Electrons are found in the nucleus of an ordinary atom.Basic2 pts

True

False

18.The mass number includes electrons.Intermediate2 pts

True

False

19.Gas particles are generally farther apart than particles in a liquid.Basic2 pts

True

False

20.A solution can contain more than one solute.Basic2 pts

True

False

21.A primary cell is designed to be easily recharged repeatedly.Intermediate2 pts

True

False

22.Oxidation state is a useful bookkeeping idea in redox chemistry.Advanced2 pts

True

False

23.Carbon can form four covalent bonds in many organic compounds.Intermediate2 pts

True

False

24.The products of a reaction always have exactly the same properties as the reactants.Basic2 pts

True

False

25.A salt bridge can help complete the internal ionic circuit of a galvanic cell.Advanced2 pts

True

False

Section C — Fill in the Blank

20 marks

10 questions · 2 marks each. Type the missing term or value.

26.The positively charged ion is called a ______.Intermediate2 pts

27.The negatively charged ion is called an ______.Intermediate2 pts

28.The total number of protons and neutrons is the ______ number.Basic2 pts

29.The process by which a gas changes to a liquid is ______.Basic2 pts

30.A mixture that has uniform composition throughout is ______.Intermediate2 pts

31.A substance that conducts electricity in aqueous solution by producing ions is an ______.Intermediate2 pts

32.In an electrochemical cell, chemical energy may be converted to ______ energy.Basic2 pts

33.A molecule with a carbon-carbon double bond is an ______.Intermediate2 pts

34.The pH scale is commonly used to describe the acidity or ______ of an aqueous solution.Intermediate2 pts

35.At equilibrium, the forward and reverse reaction rates are ______.Advanced2 pts

Section D — Matching

10 marks

5 sub-questions · 2 marks each. Match each sub-question in Column A with the correct entry in Column B.

36.Match each term in Column A with the correct description in Column B.Advanced10 pts

Column A

36(a). Mass number

36(b). Neutralization

36(c). Salt bridge

36(d). Alkane

36(e). Condensation

Column B

Salt bridge

Alkane

Condensation

Mass number

Neutralization

Section E — Short Answer

20 marks

5 questions · 4 marks each. Answer in one or two clear sentences.

41.Define an acid and a base using a simple aqueous description.Basic4 pts

42.What is the difference between mass number and atomic number?Basic4 pts

43.Explain why evaporation can occur below the boiling point.Intermediate4 pts

44.How does concentration affect collision frequency in many reactions?Intermediate4 pts

45.Explain why corrosion of iron is considered an electrochemical process.Advanced4 pts