Question

1.Why should a magnesium ribbon be cleaned before burning in air?
2.Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate → Barium sulphate +
Aluminium chloride
(iii) Sodium + Water Sodium hydroxide + Hydrogen
gas​

Answer 1

Answer:

hope its helpful

Explanation:

1) The magnesium ribbon should be cleaned before burning in the air because the layer of magnesium oxide (which is formed due to the reaction of magnesium with air ) can be removed in order to get the desired chemical reaction.  

Also in order to remove the oxide layer, the presence of which slowdowns the oxidation process. So, by cleaning it, the burning process takes place easily.

2)

Answer 2

$\LARGE{ \underline{ \purple{ \sf{Required \: answer:}}}}$

Here are the answers of questions provided above:

1️⃣ Magnesium is a reactive metal and react with Oxygen (a reagent) in the atmosphere when exposed for a longer period of time. The reaction may result in the formation of another compound which will not result in our experiment. The reaction is:

$\cdot{\large{ \boxed{ \sf{2Mg + O_2 \longrightarrow \: 2MgO}}}}$

Magnesium oxide will not burn properly, hence we need to remove it from the surface of metal by using a sand paper. We can rub it to remove the oxide layer.

━━━━━━━━━━━━━━━━━━━━

2️⃣ We have to write the balanced equations of the given word equations of different reactions. The balanced equations are as below:

a) Hydrogen + Chlorine gives Hydrogen Chloride

• $\sf{H_2 + Cl_2 \longrightarrow 2HCl}$

b) Barium chloride + Aluminium sulphate gives Barium sulphate + Aluminium chloride

• $\sf{3BaCl_2 + Al_2(SO_4)_3 \longrightarrow 2AlCl_3 + 3BaSO_4 \downarrow}$

[ Down arrow represents the precipitate ]

c) Sodium + Water gives Sodium hydroxide + Hydrogen gas

• $\sf{2Na + 2H_2O \longrightarrow 2NaOH + H_2 \uparrow}$

And we are done !!