Air, combustion, rusting and fire fighting questions | form one Chemistry

Define the following terminologies;

a)rust

b)rusting

c)mention the three necessary conditions for iron/steel to rust

Answer / Solution

ANSWERS;

a)Rust is a reddish brown substance which is formedon the surface of iron or steel.

b)Rusting is a process where a reddish brown substance is formed on the surface of iron or steel.

c)The three necessary conditions for iron to rust are ;

i) iron/steel    ii) water/moisture   and  iii) oxygen

1)i. What is air?

  ii) mention composition of the following gases in the atmosphere;

    a)0xygen    b) Carbondioxide  c) nitrogen  and  d) Argon

iii) is air a mixture or compound? explain briefly.

Answer / Solution

1)i. Air is a mixture of several gases for example oxygen, carbondioxide and other else.

  ii) the composion of the given gases in the atmosphere are:

    a)21%    b) 0.03     c)  78 nitrogen d) 0.9 argon

  iii) Air is a mixture, because it involves physical combination of several gases

1)Define the followings;

   i. Firefighting

   ii.flame

   iii.mention the necessary conditions needed to start a fire.

   iv) does oxygen burn or supports combustion?

Answer / Solution

1) i.Firefighting is the process of extinguishing/stoping harmful fire by eliminating one of the component needed to start a fire.

  ii)Flame is the region of burning substances which gives out heat  and light

 iii) the necessary  copnditions to start a fire are;

     a) oxygen  b) fuel and    C) heat

iv) oxygen does not burn rather it supports combuastion.

Give four properties of hydrogen.

Answer / Solution

UNSOLVED

When a burning splint is introduced into a gas jar containing carbon dioxide, the flame goes out.
(i) What two properties of carbon dioxide does this experiment illustrate?
(ii) What type of equipment used widely in everyday life makes use of these two properties?

Answer / Solution

UNSOLVED