📄 All MCQs
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Which row describes the type of bonding present in substances 1 and 2? Substance 1: Potassium chloride | Substance 2: Methane
💡 Explanation: Potassium chloride is an ionic compound. Methane (CH4) has covalent bonding between carbon and hydrogen atoms.
Which statement does NOT describe a property of a weak acid in solution?
💡 Explanation: A weak acid has a pH below 7 (acidic) not between 8 and 9 which would be basic.
Which does NOT describe a reaction at equilibrium?
💡 Explanation: At equilibrium Kc is constant not increasing. Kc only changes with temperature.
For which combination of acids and bases is the titration method of preparation suitable?
💡 Explanation: Titration requires both the acid and base to be soluble so they can react completely in solution.
Which does NOT increase the rate of reaction by affecting the number or nature of collisions?
💡 Explanation: A catalyst provides an alternative reaction pathway with lower activation energy but does not affect collision frequency or nature.
Which of the following changes is endothermic?
💡 Explanation: Decomposition of water requires energy input (endothermic) to break bonds between hydrogen and oxygen.
A mixture produces a gas both when it reacts with an acid and when it reacts with an alkali. Which ions are present?
💡 Explanation: Ammonium ions react with alkali to produce ammonia gas and carbonate ions react with acid to produce CO2.
In a Redox reaction electrons are transferred from:
💡 Explanation: In a redox reaction the reducing agent loses (donates) electrons to the oxidizing agent.
Soap-making process in industries is known as:
💡 Explanation: Saponification is the chemical process of making soap by reacting fats or oils with a strong base.
The equation MgCO3 → MgO + CO2 (Mr=84). Which mass of MgO is formed when 21.0g of MgCO3 are completely decomposed?
💡 Explanation: Moles of MgCO3 = 21/84 = 0.25 mol. Moles of MgO = 0.25 mol. Mass of MgO = 0.25 × 40 = 10.0g.
The diagram shows arrangement of particles changing from closely packed to spaced out. Which change of state is shown?
💡 Explanation: Boiling is the change of state from liquid to gas involving rapid separation of particles.
X-rays are produced when cathode rays strike on:
💡 Explanation: X-rays are produced when high-energy cathode rays (electrons) strike a metal target.