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WBJEE Chemistry Questions
Practise chemistry (science) for the West Bengal Joint Entrance Examination: 10 multiple-choice questions, each with the correct answer and a worked explanation. Click an option to check it, or “New questions” for another set.
Chemistry practice
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Q1.Water has a maximum density at about:
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Answer: B — 4 °C
Water is densest at about 4 °C.
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Q2.What is the mass of 1 mol of carbon dioxide (CO₂)? (Molar mass 44 g/mol)
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Answer: D — 44 g
Mass = moles × molar mass = 1 × 44 g/mol = 44 g.
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Q3.The hardest naturally occurring substance is:
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Answer: D — Diamond
Diamond, a carbon allotrope, is the hardest natural material.
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Q4.What is the pH of a solution with [OH⁻] = 10⁻⁶ mol/L at 25 °C?
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Answer: D — 8
[OH⁻] = 10⁻⁶ → pOH = 6; pH = 14 − 6 = 8 (at 25 °C).
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Q5.Avogadro’s number is approximately:
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Answer: A — 6.022 × 10²³
One mole contains 6.022 × 10²³ particles.
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Q6.What is the mass of 4 mol of carbon dioxide (CO₂)? (Molar mass 44 g/mol)
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Answer: D — 176 g
Mass = moles × molar mass = 4 × 44 g/mol = 176 g.
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Q7.Which element is liquid at room temperature?
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Answer: A — Mercury
Mercury (and bromine) are liquids at room temperature.
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Q8.What is the mass of 1.5 mol of sodium chloride (NaCl)? (Molar mass 58.5 g/mol)
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Answer: D — 87.75 g
Mass = moles × molar mass = 1.5 × 58.5 g/mol = 87.75 g.
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Q9.Which gas is produced when zinc reacts with dilute hydrochloric acid?
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Answer: D — Hydrogen
Zn + 2HCl → ZnCl₂ + H₂.
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Q10.What is the mass of 2 mol of glucose (C₆H₁₂O₆)? (Molar mass 180 g/mol)
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Answer: A — 360 g
Mass = moles × molar mass = 2 × 180 g/mol = 360 g.
How to approach chemistry questions
Moles = mass ÷ molar mass; molarity = moles ÷ litres. pH = −log[H⁺] and pH + pOH = 14 at 25 °C. For concepts, link each property to its position in the periodic table.
About WBJEE
West Bengal Joint Entrance Examination — conducted by West Bengal Joint Entrance Examinations Board (WBJEEB). State engineering, technology and pharmacy entrance for West Bengal.
Original practice questions written for this site in the style and difficulty of each exam’s syllabus. They are not past papers and the site is not affiliated with any exam body. Exam patterns, marking schemes and syllabi change — always check the latest official notification.
WBJEE practice topics
| Topic | Section | Question source |
|---|---|---|
| Algebra | Mathematics | Calculated (new numbers every set) |
| Probability & Combinatorics | Mathematics | Calculated (new numbers every set) |
| Physics | Science | Calculated + question bank |
| Chemistry | Science | Calculated + question bank |