Kuiz Sains Tambahan Tingkatan 5 Bab 2 Set 1

SELAMAT DATANG Kuiz Sains Tambahan Tingkatan 5 Bab 2 Set 1

Penerokaan Unsur Dalam Alam (English)

KUIZ INI MENGANDUNGI 10 SOALAN

Which of the following methods is most suitable for preparing a pure, dry sample of the insoluble salt lead(II) iodide (PbI2)?

Mixing aqueous solutions of lead(II) nitrate and potassium iodide.

Reacting lead metal with iodine solution.

Heating solid lead(II) nitrate with solid potassium iodide.

Reacting lead(II) oxide with hydroiodic acid

None

A gas produced during a chemical reaction is tested by bubbling it through limewater, which turns milky. What is this gas?

Oxygen (O2)

Hydrogen (H2)

Carbon dioxide (CO2)

Ammonia (NH3)

None

A student adds sodium hydroxide solution to an unknown salt solution, forming a white precipitate. When excess sodium hydroxide is added, the precipitate dissolves to form a colorless solution. Based on the provided flowcharts, which cation could be present?

Zinc ion (Zn2+)

Magnesium ion (Mg2+)

Copper(II) ion (Cu2+)

Iron(III) ion (Fe3+)

None

A student adds aqueous ammonia dropwise to a solution containing copper(II) ions until the ammonia is in excess. What is the expected final observation?

A white precipitate forms and then dissolves to form a colorless solution.

A blue precipitate forms and remains insoluble.

A light blue precipitate forms and then dissolves to form a dark blue solution.

A dirty green precipitate forms and remains insoluble.

None

During a qualitative analysis, an aqueous solution is observed to be blue. Which cation is most likely present in the salt solution?

Iron(II) ion (Fe2+)

Iron(III) ion (Fe3+)

Copper(II) ion (Cu2+)

Zinc ion (Zn2+)

None

What is the most suitable method for preparing an insoluble salt like lead(II) sulfate (PbSO4)?

Double decomposition (precipitation)

Titration of an acid with an alkali

Reacting a metal carbonate with a dilute acid

Reacting a reactive metal with a dilute acid

None

A student performs a flame test on a salt and observes no distinct color. Then, the student adds sodium hydroxide solution to an aqueous solution of the salt and gently warms it. A gas is produced that turns damp red litmus paper blue. Which cation is present?

Zinc ion

Ammonium ion

Sodium ion

Calcium ion

None

A student heats a white crystalline salt in a test tube. The residue is yellow when hot and turns white upon cooling. A gas is also produced that turns limewater cloudy. What is the most likely identity of the salt?

Lead(II) carbonate

Copper(II) carbonate

Zinc carbonate

Magnesium carbonate

None

In the reaction MgCO3 + 2HCl→MgCl2 + CO2 + H2O, what is the mole ratio of magnesium carbonate (MgCO3) to hydrochloric acid (HCl) that is required for a complete reaction?

1:2

1:1

1:3

2:1

None

10.

During the preparation of copper(II) chloride from copper(II) oxide and hydrochloric acid, why is the copper(II) oxide powder added in excess?

To prevent the salt from decomposing upon heating.

To ensure all of the hydrochloric acid has reacted completely.

To act as a catalyst for the reaction.

To increase the concentration of the final salt solution.

None

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