Tag: reaction of metals

Questions Related to reaction of metals

Zinc metal burns in air only on strong heating to form :

  1. zinc chloride

  2. zinc sulphide

  3. zinc oxide

  4. zinc hydroxide


Correct Option: C
Explanation:

Zinc metal burns in air only on strong heating to form zinc oxide.

$Zinc + Oxygen \xrightarrow{\Delta} Zinc\,oxide$

$2Zn + O _2 \xrightarrow{\Delta} 2ZnO$

When a copper vessel is exposed to moist air for a longer time. It aquires a dull green coating then the correct statement is 

  1. It contains copper hydroxide

  2. It contains copper carbonate

  3. It is formed when copper reacts with moist air

  4. None of these


Correct Option: A

The amphoteric metallic oxide is:

  1. calcium oxide

  2. barium oxide

  3. zinc oxide

  4. copper (II) oxide


Correct Option: C
Explanation:

 An amphoteric oxide is an oxide that can act as either an acid or base in a reaction.
$Al _2O _3$ is an amphoteric oxide. When reacted with HCl, it acts as a base to form the salt $AlCl _3$. When reacted with NaOH, it acts as an acid to form $NaAlO _2$.
also, zinc oxide is an amphoteric oxide.

Which one of the following is basic oxide?

  1. Nitrous oxide

  2. Nitric oxide

  3. Carbon monoxide

  4. Zinc oxide


Correct Option: D
Explanation:
Metals generally form basic  oxides, some of which are also amphoteric, such as aluminium  oxide, zinc oxide, lead oxide etc.
Non-metals generally form acidic oxides. Some oxides are neutral, such as nitrous oxide, nitric oxide, carbon monoxide water etc.

Name one metal in each part fitting the given description:

A metal that burns in oxygen with a bright light

  1. Magnesium

  2. Iron

  3. Aluminium

  4. None of the above


Correct Option: A
Explanation:

Magnesium is a metal that burns in oxygen with a bright light and the reaction can be written as:
$2Mg + O _{2} \rightarrow 2MgO$

Which metal is stored in kerosene oil?

  1. Sodium

  2. Calcium

  3. Iron

  4. None of the above


Correct Option: A
Explanation:

The metal stored in kerosene oil is Sodium(Na).

Name two product of the given reaction.

$Zn   + \underset{(Steam)}{H _2O}    \rightarrow       $

  1. Zinc oxide, hydrogen

  2. Zinc, water

  3. Zinc oxide, water

  4. Zinc, hydrogen


Correct Option: A
Explanation:

$ Zn + H _{2}O \rightarrow ZnO + H _{2}$
          (steam)

Which metals react with cold water?

  1. Sodium, calcium, magnesium

  2. Iron, calcium, magnesium

  3. Iron, sodium, magnesium

  4. Potassium, sodium, magnesium


Correct Option: A
Explanation:

The metals which react with cold water are; sodium, calcium and magnesium.

Which metal does not react with water?

  1. $Cu$

  2. $Au$

  3. Both A and B

  4. $Fe$


Correct Option: C
Explanation:

Copper, silver and gold are unreactive metals and do not react with water or mild acids. 

Which of the metals will not react with oxygen when heated?

  1. Gold

  2. Iron

  3. Sodium

  4. None of the above


Correct Option: A
Explanation:

Gold is a noble metal which does not react with oxygen on heating.