Kuiz Sains Tambahan Tingkatan 5 Bab 4 Set 1

SELAMAT DATANG Kuiz Sains Tambahan Tingkatan 5 Bab 4 Set 1

Tenaga Dan Perubahan Kimia (English)

KUIZ INI MENGANDUNGI 10 SOALAN

During the electrolysis of a dilute aqueous sodium chloride (NaCl) solution using inert electrodes, what gas is produced at the anode?

Chlorine

Hydrogen

Sodium

Oxygen

None

When electroplating an iron spoon with copper, which of the following setups is correct?

The iron spoon is the anode, and a copper bar is the cathode.

The electrolyte is a solution of iron(II) sulfate.

The iron spoon is the cathode, and the electrolyte is copper(II) sulfate.

Both the anode and cathode are made of iron.

None

Which of the following reaction equations represents an endothermic process?

Zn+2HCl→ZnCl2 +H2 ΔH = −152 kJ mol−1

C+2S→CS 2 ΔH=+320 kJ mol−1

C2H5OH + 3O2 →2CO2 + 3H2O ΔH = −1270 kJ mol−1

2Mg + O2 →2MgO ΔH = −1204 kJ mol−1

None

In the industrial process of purifying copper, what is the role of the impure copper block?

It acts as the anode, which dissolves during electrolysis

It serves as the cathode, where pure copper is deposited.

It is used to stir the electrolyte solution.

It functions as the electrolyte for the cell

None

A chemical reaction has a change in enthalpy value of ΔH=−1204 kJ mol−1. Which statement accurately describes this reaction?

The products have a higher energy content than the reactants.

The reaction is endothermic, absorbing heat from the surroundings.

The surroundings would feel colder as the reaction proceeds.

The reaction is exothermic, releasing heat into the surroundings.

None

In an experiment to measure the heat of displacement, a plastic cup is used as the calorimeter. What is the main reason for this choice?

Plastic is transparent, allowing for better observation.

Plastic is less reactive than glass with the chemical solutions.

Plastic is a good insulator, minimizing heat loss to the surroundings.

Plastic cups are cheaper and more readily available than glass beakers.

None

What is the primary function of adding cryolite (Na3AlF6) to aluminium oxide (Al2O3) during the industrial extraction of aluminium?

To significantly lower the melting point of aluminium oxide.

To increase the purity of the final aluminium product.

To act as a catalyst and speed up the reaction.

To prevent the carbon anodes from oxidizing.

None

In a photochromic lens, what causes the glass to darken upon exposure to sunlight?

The glass absorbs light and then releases it as heat.

Silver halide crystals decompose into dark silver particles.

A heat-sensitive dye embedded in the glass changes color

The glass undergoes a permanent chemical change

None

What happens to the electrons at the positive terminal (cathode) of a simple chemical cell, such as one made of zinc and copper?

They combine with the atoms of the cathode material.

They are accepted by positive ions from the electrolyte.

They flow from the cathode to the anode through the external wire.

They are released by the copper electrode into the solution.

None

10.

Which energy transformation occurs in an electrolytic cell?

Electrical energy to chemical energy

Heat energy to electrical energy

Light energy to chemical energy

Chemical energy to electrical energy

None

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