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

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

The glass absorbs light and then releases it as heat.

The glass undergoes a permanent chemical change

Silver halide crystals decompose into dark silver particles.

A heat-sensitive dye embedded in the glass changes color

None

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

Oxygen

Sodium

Chlorine

Hydrogen

None

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

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.

The products have a higher energy content than the reactants.

None

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

It is used to stir the electrolyte solution.

It acts as the anode, which dissolves during electrolysis

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

It functions as the electrolyte for the cell

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 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.

Plastic is transparent, allowing for better observation.

None

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

To act as a catalyst and speed up the reaction.

To significantly lower the melting point of aluminium oxide.

To increase the purity of the final aluminium product.

To prevent the carbon anodes from oxidizing.

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

They combine with the atoms of the cathode material.

They are released by the copper electrode into the solution.

They are accepted by positive ions from the electrolyte.

None

Which energy transformation occurs in an electrolytic cell?

Chemical energy to electrical energy

Electrical energy to chemical energy

Light energy to chemical energy

Heat energy to electrical energy

None

Which of the following reaction equations represents an endothermic process?

2Mg + O2 →2MgO ΔH = −1204 kJ mol−1

C+2S→CS 2 ΔH=+320 kJ mol−1

Zn+2HCl→ZnCl2 +H2 ΔH = −152 kJ mol−1

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

None

10.

What is the specific process that uses light energy to split water molecules into hydrogen ions and oxygen during photosynthesis?

Photosynthesis

Electrolysis

Hydrolysis

Photolysis

None

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