Question

how are these impurities in hydrogen removed​

Answer 1

Answer:

The impurities can be removed from hydrogen by passing it through

1. Silver nitrate solution to remove arsine and phosphine.

AsH3+6AgNO3→Ag3As+3AgNO3+3HNO3

PH3+6AgNO3→Ag3P+3AgNO3+3HNO3

2. Lead nitrate solution to remove hydrogen sulphide.

Pb(NO3)2+H2S→PbS+2HNO3

Caustic potash solution to remove sulphur dioxide, carbon dioxide and oxides of nitrogen.

SO2+2KOH→K2SO3+H2O

CO2+2KOH→K2CO3+H2O

2NO2+2KOH→KNO2+KNO3+H2O

4. A drying agent used to dry the gas. Common drying agents such as fused calcium chloride, caustic potash stick and phosphorus pentoxide remove water vapour.

So, the gas is purified and dried and then collected over mercury because mercury does not react with it.

Answer 2

Question-

How can the impurities present in hydrogen prepared in the laboratory be removed?

Answer-

The impurities present in hydrogen prepared in the laboratory are as follows-

• Hydrogen Sulphide
• Sulphur Dioxide
• Oxides Of Nitrogen
• Phosphine (PH₃)
• Carbon Dioxide
• Water Vapour

Crude hydrogen gas containing carbon dioxide and hydrogen sulfide impurities are scrubbed with aqueous liquid triethanolamine solution (C₆H₁₅NO₃) to remove the impurities from the hydrogen gas.

Triethanolamine, or TEA is a viscous organic compound that is both a tertiary amine and a triol. A triol is a molecule with three alcohol groups.