Chemistry Quiz on Metals

Gold is soluble in which of the following:

• silver

• iron

• Aquarezia

• Mercury

Answer explanation

Gold is soluble in Aquarezia, which is a mixture of hydrochloric and nitric acids, commonly used to dissolve noble metals. The other options, silver, iron, and mercury, do not dissolve gold.

.......... is the most ductile metal.

• Cu

• Al

• Au

• Zn

Answer explanation

Gold (Au) is the most ductile metal, capable of being drawn into extremely thin wires. It surpasses other metals like copper (Cu), aluminum (Al), and zinc (Zn) in ductility, making it the correct answer.

Chemical formula K2SO4 represents. . . . . . . .

• potassium nitrate

• potassium chloride

• Potassium sulphate

• Aluminium sulphate

Answer explanation

The chemical formula K2SO4 indicates that it contains two potassium (K) ions, one sulfate (SO4) ion, making it potassium sulphate. The other options do not match this composition.

Which of the following metals reacts quickly with cold water?

• Potassium

• Aluminium

• zinc

• iron

Answer explanation

Potassium reacts vigorously with cold water, producing hydrogen gas and heat. In contrast, aluminium, zinc, and iron react much more slowly or not at all with cold water, making potassium the correct choice.

The chemical symbol K of ....... is derived from the Latin word 'Kalium'.

• argentum

• Vulfrem

• stannum

• potassium

Answer explanation

The chemical symbol K stands for potassium, which comes from the Latin word 'Kalium'. The other options, such as argentum (silver), Vulfrem (tungsten), and stannum (tin), do not relate to the symbol K.

Which of the following is used for water purification?

• vinegar

• baking soda

• alum

• tartaric acid

Answer explanation

Alum is commonly used in water purification processes as a coagulant. It helps to remove impurities and clarify water, making it the correct choice among the options provided.

Which of the following can be used for purification of water?

• Nitrogen

• Alum

• Sodium

• Carbon

Answer explanation

Alum is commonly used for water purification as it helps in coagulating impurities, making them easier to remove. Nitrogen, sodium, and carbon do not serve this purpose effectively.

Alum is an example of this.

• Double salt

• table salt

• Flak salt

• Single salt

Answer explanation

Alum is a type of double salt, which consists of two different salts crystallized together. It is distinct from table salt, flake salt, and single salts, making 'double salt' the correct choice.

Molecular formula of potassium nitrate is. . . . .

• KNO3

• KNO2

• KNO4

• KNO

Answer explanation

The molecular formula of potassium nitrate is KNO3, which consists of one potassium (K), one nitrogen (N), and three oxygen (O) atoms. The other options do not represent potassium nitrate.

Which of the following metals is required to be kept in oil?

• Gold

• Potassium

• iron

• silver

Answer explanation

Potassium is highly reactive, especially with water, and must be stored in oil to prevent it from reacting with moisture in the air. Gold, iron, and silver do not require such storage conditions.