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 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

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 increase the purity of the final aluminium product.

To act as a catalyst and speed up the reaction.

To prevent the carbon anodes from oxidizing.

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 acts as the anode, which dissolves during electrolysis

It is used to stir the electrolyte solution.

It functions as the electrolyte for the cell

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 released by the copper electrode into the solution.

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

They combine with the atoms of the cathode material.

They are accepted by positive ions from the electrolyte.

None

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

A heat-sensitive dye embedded in the glass changes color

The glass undergoes a permanent chemical change

Silver halide crystals decompose into dark silver particles.

The glass absorbs light and then releases it as heat.

None

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

Copper ions from the solution deposit onto the magnesium strip.

Magnesium atoms lose electrons to become magnesium ions.

Electrons from the copper strip react with the magnesium.

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

None

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

To protect them from decomposition caused by light.

To prevent chemical reactions with the glass container.

To prevent them from evaporating quickly.

To keep the chemicals at a constant cool temperature.

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

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

Chlorine

Sodium

Oxygen

Hydrogen

None

10.

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 cups are cheaper and more readily available than glass beakers.

Plastic is transparent, allowing for better observation.

Plastic is a good insulator, minimizing heat loss to the surroundings.

None

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