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

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

The surroundings would feel colder as the reaction proceeds.

The products have a higher energy content than the reactants.

The reaction is exothermic, releasing heat into the surroundings.

The reaction is endothermic, absorbing heat from the surroundings.

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 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.

None

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

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.

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

None

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

Hydrogen

Chlorine

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 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

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

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

The glass absorbs light and then releases it as heat.

None

During the electrolysis of molten lead(II) bromide (PbBr2), which products are formed at the anode and cathode respectively?

Lead(II) ions at the anode and bromide ions at the cathode.

Bromine gas at the anode and lead metal at the cathode.

Hydrogen gas at the cathode and oxygen gas at the anode.

Lead metal at the anode and bromine gas at the cathode.

None

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

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

Electrons from the copper strip react with the magnesium.

Copper ions from the solution deposit onto the magnesium strip.

Magnesium atoms lose electrons to become magnesium ions.

None

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

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.

To act as a catalyst and speed up the reaction.

None

10.

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

Photosynthesis

Photolysis

Hydrolysis

Electrolysis

None

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