51.

Write the equation for the reaction of the dilute Nitric acid with copper?

Account for the yellow colour that appears in concentrated Nitric acid when it left standing in an ordinary glass bottle.

Which feature of the Ammonia molecule leads to the formation of the Ammonium ion when Ammonia dissolves in water? 

Name the other ion formed when Ammonia dissolves in water. 

Give  one test that can be used to detect  the presence of the ion produced in (b) (ii) .

Write the equations for the following reactions which result in the formation of Ammonia:-
1) A mixture of Ammonium chloride and slaked lime is heated.

2) Aluminium nitride and water.

Calculate the percentage of Nitrogen in Aluminium nitride.

The equations given below relate to the manufacture of sodium carbonate (molecular weight of Na₂CO₃ =106).
1. NaCl +NH₃ +CO₂ +H₂O ---> NaHCO₃ +NH₄Cl
2. 2NaHCO₃ ---> Na₂CO₃ +H₂O +CO₂
Question a and b are based on the production of 21.2 g of sodium carbonate.

a. what mass of sodium hydrogen carbonate must be heated to give 21.2 g of sodium carbonate (molecular weight of NaHCO₃ =84)?

b. To produce the mass of sodium hydrogen carbonate calculated in (a), what volume of Carbon dioxide, measured at S.T.P., would be required? 

Define the following terms:-

1) Atomic weight

2) Catenation

[Calcium, copper Lead, Aluminium, Zinc, Chromium, Magnesium, Iron.]

Choose the major metals from the list given above to make the following alloys:-

1) Stainless steel.

2) Brass