NCERT Class X Science Class: Chapter –3. Metals and Nonmetals– Part-8

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Question 44:

The following reaction takes place when aluminium powder is heated with

Heat

  1. Is aluminium getting reduced?

  2. Is getting oxidised?

Answer:

  1. No, because oxygen is added to aluminium therefore, it is getting oxidised

  2. No, since manganese has lost oxygen therefore, it is getting reduced.

Question 45:

What the constituents are of solder alloy? Which property of solder makes it suitable for welding electrical wires?

Answer:

Solder is an alloy of lead and tin. Low melting point of solder makes it suitable for welding electrical wires.

Image low melting point solder wire

Image Low Melting Point Solder Wire

Image low melting point solder wire

Question 46:

A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with

Answer:

Metal A is aluminum oxide and B is aluminum oxide reaction with

Question 47:

A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reaction involved.

Answer:

Metals low in activity series can be obtained by reducing their sulphide or oxides by heating. Mercury is the only metal that exists as liquid at room temperature. It can be obtained by heating cinnabar the sulphide ore of mercury.

The reactions are as follows:

Question 48:

Give the formulae of the stable binary compounds that would be formed by the combination of following pairs of elements.

Answer:

  1. Lithium oxide

Question 49:

What happens when?

  1. is heated in the absence of oxygen?

  2. A mixture of and is heated?

Answer:

When zinc carbonate heated in absence of air, it releases CO2 gas and forms

It undergoes calcination. The chemical reaction can be given as

It undergoes auto reduction forming copper and sulphur dioxide