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 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 cups are cheaper and more readily available than glass beakers.

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.

None

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

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

It acts as the anode, which dissolves during electrolysis

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 prevent the carbon anodes from oxidizing.

To significantly lower the melting point of aluminium oxide.

To increase the purity of the final aluminium product.

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 are accepted by positive ions from the electrolyte.

They are released by the copper electrode into the solution.

They combine with the atoms of the cathode material.

None

Which of the following reaction equations represents an endothermic process?

C+2S→CS 2 ΔH=+320 kJ mol−1

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

Zn+2HCl→ZnCl2 +H2 ΔH = −152 kJ mol−1

2Mg + O2 →2MgO ΔH = −1204 kJ mol−1

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 exothermic, releasing heat into the surroundings.

The surroundings would feel colder as the reaction proceeds.

The reaction is endothermic, absorbing heat from the surroundings.

None

Which energy transformation occurs in an electrolytic cell?

Electrical energy to chemical energy

Light energy to chemical energy

Heat energy to electrical energy

Chemical energy to electrical energy

None

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

Oxygen

Sodium

Hydrogen

Chlorine

None

Why are photosensitive chemicals such as silver bromide and hydrogen peroxide typically stored in dark or opaque bottles?

To prevent chemical reactions with the glass container.

To protect them from decomposition caused by light.

To prevent them from evaporating quickly.

To keep the chemicals at a constant cool temperature.

None

10.

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

The glass undergoes a permanent chemical change

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

None

1 out of 10