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

Oxygen

Sodium

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 functions as the electrolyte for the cell

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

It is used to stir the electrolyte solution.

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

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 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.

The glass undergoes a permanent chemical change

A heat-sensitive dye embedded in the glass changes color

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 prevent the carbon anodes from oxidizing.

To increase the purity of the final aluminium product.

None

In a simple chemical cell constructed with magnesium and copper electrodes in an electrolyte, why does the magnesium strip become thinner over time?

Magnesium atoms lose electrons to become magnesium ions.

Electrons from the copper strip react with the magnesium.

Copper ions from the solution deposit onto the magnesium strip.

The magnesium strip physically flakes off due to the electric current.

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

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

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

Both the anode and cathode are made of iron.

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

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

None

10.

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

Hydrolysis

Photolysis

Electrolysis

Photosynthesis

None

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