Join WhatsApp ChannelDaily MCQs & Exam Updates

Chemistry MCQs

235 Questions Subject Test
Subject Preparation Guide

Prepare Chemistry with confidence

Practice the essential concepts of matter, atomic structure, chemical reactions, bonding and everyday applications of chemistry.

Atomic StructureChemical BondingReactionsOrganic Chemistry
Helpful for board examinations, entry tests and science-based competitive papers.
Chemistry preparation illustration
Subject Test

Test your Chemistry preparation

Questions are tracked as practiced when you open Show Answer & Explanation. Tracking stays only in this browser tab and no subject-test result is saved.

Practiced MCQs
0 / 235
Use the MCQs you already prepared, or launch a random test from the full subject bank.
No login required Result is not saved Choose your own MCQ count & timer
Choose your test mode
Choose any number up to 235 available MCQs.
Enter 0 for no timer, or choose 1–300 minutes.
Tip: prepare some MCQs first, then start a quick self-check from My Practiced MCQs to test exactly what you studied.
Filter: All Exams css pms fpsc ppsc nts | All Easy Medium Hard
141
Medium nts Uploaded: 07 Aug 2026

Which of the following is used to detect the presence of starch?

  • A Iodine solution
  • B Litmus paper
  • C Bromine water
  • D Fehling's solution
Permalink
Correct Answer: Option A — Iodine solution
Explanation: Iodine solution is used to detect the presence of starch, turning from brown to a deep blue-black color when it reacts with starch molecules. This simple test is commonly performed in biology and chemistry laboratories.
Submitted by: PaperMCQs
142
Medium fpsc ppsc nts Uploaded: 14 Jul 2026

Which gas is responsible for the distinctive smell of rotten eggs?

  • A Methane
  • B Hydrogen sulfide
  • C Ammonia
  • D Sulfur dioxide
Permalink
Correct Answer: Option B — Hydrogen sulfide
Explanation: Hydrogen sulfide H2S is a colourless toxic gas responsible for the characteristic smell of rotten eggs and is produced by the bacterial decomposition of organic matter.
Submitted by: PaperMCQs
143
Easy pms Uploaded: 06 Aug 2026

Which element is the lightest gas known?

  • A Helium
  • B Hydrogen
  • C Nitrogen
  • D Oxygen
Permalink
Correct Answer: Option B — Hydrogen
Explanation: Hydrogen is the lightest and most abundant element in the universe, consisting of just one proton and one electron. Due to its low density, hydrogen gas rises quickly in air and is used in various industrial applications.
Submitted by: PaperMCQs
144
Easy nts Uploaded: 07 Aug 2026

What is the term for a mixture of two or more metals?

  • A Compound
  • B Alloy
  • C Solution
  • D Colloid
Permalink
Correct Answer: Option B — Alloy
Explanation: An alloy is a mixture of two or more metals, or a metal combined with a nonmetal, designed to enhance properties such as strength, corrosion resistance, or durability. Bronze and steel are common examples of alloys.
Submitted by: PaperMCQs
145
Medium css fpsc ppsc Uploaded: 05 Aug 2026

Which process adds water to a compound to break chemical bonds in organic reactions?

  • A Dehydration
  • B Oxidation
  • C Reduction
  • D Hydrolysis
Permalink
Correct Answer: Option D — Hydrolysis
Explanation: Hydrolysis literally meaning water splitting is the chemical process where water reacts with a compound breaking bonds and splitting the molecule into two or more parts.
Submitted by: PaperMCQs
146
Medium fpsc ppsc nts Uploaded: 14 Jul 2026

What is the chemical name of the compound with formula CuSO4?

  • A Copper sulfide
  • B Copper sulfite
  • C Copper carbonate
  • D Copper sulfate
Permalink
Correct Answer: Option D — Copper sulfate
Explanation: CuSO4 is copper sulfate a blue crystalline compound used in agriculture as a fungicide in electroplating and as a laboratory reagent for testing reducing sugars.
Submitted by: PaperMCQs
147
Easy ppsc Uploaded: 07 Aug 2026

Which term describes elements in the same column of the periodic table?

  • A Series
  • B Blocks
  • C Periods
  • D Groups
Permalink
Correct Answer: Option D — Groups
Explanation: Elements arranged in the same vertical column of the periodic table are called groups. Elements within a group share similar chemical properties because they have the same number of valence electrons in their outer shell.
Submitted by: PaperMCQs
148
Easy fpsc ppsc nts Uploaded: 14 Jul 2026

What is the chemical formula for ammonia?

  • A NO2
  • B N2H4
  • C NH3
  • D NH4
Permalink
Correct Answer: Option C — NH3
Explanation: Ammonia has the chemical formula NH3 consisting of one nitrogen atom bonded to three hydrogen atoms and is widely used in fertiliser production and as a cleaning agent.
Submitted by: PaperMCQs
149
Easy fpsc ppsc nts Uploaded: 14 Jul 2026

What is the chemical formula for hydrogen peroxide commonly used as an antiseptic?

  • A H2O2
  • B H2O
  • C H3O2
  • D HO2
Permalink
Correct Answer: Option A — H2O2
Explanation: Hydrogen peroxide H2O2 is a pale blue liquid used as an antiseptic bleaching agent and rocket propellant differing from water by having an extra oxygen atom.
Submitted by: PaperMCQs
150
Medium ppsc Uploaded: 06 Aug 2026

What is the process by which plants convert light energy into chemical energy?

  • A Respiration
  • B Fermentation
  • C Photosynthesis
  • D Transpiration
Permalink
Correct Answer: Option C — Photosynthesis
Explanation: Photosynthesis is the process by which green plants use sunlight, water, and carbon dioxide to produce glucose and oxygen. This process forms the foundation of most food chains and sustains life on Earth.
Submitted by: PaperMCQs
151
Hard css Uploaded: 07 Aug 2026

Which of the following describes Le Chatelier's Principle?

  • A Reactions always favor products
  • B Systems at equilibrium resist changes to conditions
  • C Catalysts change equilibrium position
  • D Reactions cannot reach equilibrium
Permalink
Correct Answer: Option B — Systems at equilibrium resist changes to conditions
Explanation: Le Chatelier's Principle states that when a system at equilibrium experiences a change in concentration, temperature, or pressure, it shifts in the direction that counteracts the disturbance to restore a new equilibrium state.
Submitted by: PaperMCQs
152
Medium css fpsc ppsc Uploaded: 14 Jul 2026

What is the formula for calculating moles from mass and molar mass?

  • A Moles equals mass times molar mass
  • B Moles equals molar mass divided by mass
  • C Moles equals mass divided by molar mass
  • D Moles equals mass times volume
Permalink
Correct Answer: Option C — Moles equals mass divided by molar mass
Explanation: Moles are calculated by dividing the mass of a substance in grams by its molar mass in grams per mole providing the fundamental calculation in all stoichiometry problems.
Submitted by: PaperMCQs
153
Medium nts Uploaded: 07 Aug 2026

What is the primary use of the element iodine in the human body?

  • A Blood clotting
  • B Muscle contraction
  • C Bone formation
  • D Thyroid hormone production
Permalink
Correct Answer: Option D — Thyroid hormone production
Explanation: Iodine is essential for the production of thyroid hormones, which regulate metabolism, growth, and development in the human body. Iodine deficiency can lead to goiter and other thyroid-related health complications.
Submitted by: PaperMCQs
154
Medium fpsc ppsc nts Uploaded: 14 Jul 2026

What is the chemical formula for calcium carbonate found in limestone and chalk?

  • A CaSO4
  • B Ca(OH)2
  • C CaCl2
  • D CaCO3
Permalink
Correct Answer: Option D — CaCO3
Explanation: Calcium carbonate CaCO3 is the main component of limestone chalk and marble and is also found in shells of marine organisms and is used in construction and as an antacid.
Submitted by: PaperMCQs
155
Easy nts Uploaded: 06 Aug 2026

Which subatomic particle has no electric charge?

  • A Neutron
  • B Electron
  • C Proton
  • D Ion
Permalink
Correct Answer: Option A — Neutron
Explanation: Neutrons are electrically neutral particles found in the nucleus of an atom alongside protons. They contribute to the atomic mass but do not affect the overall charge of the atom, unlike protons and electrons.
Submitted by: PaperMCQs
156
Easy nts Uploaded: 07 Aug 2026

What is the chemical formula for baking soda?

  • A Na2CO3
  • B NaHCO3
  • C NaOH
  • D NaCl
Permalink
Correct Answer: Option B — NaHCO3
Explanation: Baking soda has the chemical formula NaHCO3, known as sodium bicarbonate. It is used widely in cooking as a leavening agent, as well as in cleaning products and as a mild antacid for stomach upset relief.
Submitted by: PaperMCQs
157
Medium fpsc ppsc nts Uploaded: 05 Aug 2026

Which element is essential for synthesis of haemoglobin and its deficiency causes anaemia?

  • A Zinc
  • B Calcium
  • C Magnesium
  • D Iron
Permalink
Correct Answer: Option D — Iron
Explanation: Iron is an essential component of haemoglobin the protein in red blood cells that binds and transports oxygen and its deficiency causes iron deficiency anaemia the most common nutritional disorder.
Submitted by: PaperMCQs
158
Medium css fpsc ppsc Uploaded: 14 Jul 2026

What is the concentration of a solution measured in moles per litre called?

  • A Normality
  • B Molality
  • C Formality
  • D Molarity
Permalink
Correct Answer: Option D — Molarity
Explanation: Molarity is the measure of concentration of a solution expressed as the number of moles of solute dissolved per litre of solution with units of mol/L or M.
Submitted by: PaperMCQs
159
Hard css Uploaded: 07 Aug 2026

What is the empirical formula of benzene?

  • A C2H2
  • B C3H3
  • C C6H6
  • D CH
Permalink
Correct Answer: Option D — CH
Explanation: Benzene's molecular formula is C6H6, but its empirical formula simplifies to CH since the ratio of carbon to hydrogen atoms is 1:1. The empirical formula represents the simplest whole-number ratio of elements in a compound.
Submitted by: PaperMCQs
160
Easy ppsc nts Uploaded: 14 Jul 2026

Which gas has the chemical formula CO2?

  • A Carbon dioxide
  • B Carbon monoxide
  • C Sulfur dioxide
  • D Nitrogen dioxide
Permalink
Correct Answer: Option A — Carbon dioxide
Explanation: Carbon dioxide with the formula CO2 consists of one carbon atom double bonded to two oxygen atoms and is a major greenhouse gas produced by combustion and respiration.
Submitted by: PaperMCQs
All Subjects
Biology 210 Chemistry 235 Computer Science 477 Current Affairs 1,079
1–4 of 11Auto-changing every 5s
Academic Subjects
Physics9th Class 248
View All Academic Classes
Mock Tests
Quick Test (20 Q) Full Mock Test
Practiced MCQs0 / 235