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 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.

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

Copper ions from the solution deposit onto the magnesium strip.

Electrons from the copper strip react with the magnesium.

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 exothermic, releasing heat into the surroundings.

The surroundings would feel colder as the reaction proceeds.

The reaction is endothermic, absorbing heat from 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.

A heat-sensitive dye embedded in the glass changes color

The glass undergoes a permanent chemical change

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 act as a catalyst and speed up the reaction.

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 are accepted by positive ions from the electrolyte.

They combine with the atoms of the cathode material.

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

They are released by the copper electrode into the solution.

None

Which energy transformation occurs in an electrolytic cell?

Heat energy to electrical energy

Light energy to chemical energy

Electrical energy to chemical energy

Chemical energy to electrical energy

None

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

Electrolysis

Photosynthesis

Photolysis

Hydrolysis

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 a good insulator, minimizing heat loss to the surroundings.

Plastic is less reactive than glass with the chemical solutions.

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

None

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

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

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

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

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

None

10.

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

Both the anode and cathode are made of iron.

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

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

1 out of 10