Calculate

(i) The volume of 2.5 moles of a gas X at stp.

(ii) The weight of 2.8 dm³ of a basic gas you have learnt, at STP.

(iii) The molecular weight of a gas Y whose 5.6 litres of volume at STP weighs 3.5 gms.

(at wt of C = 12, X = 14, H = 1, O = 16)

Concentrated nitric acid oxidises phosphorus to phosphoric acid as

P + HNO₃ ⟶H₃PO₄ + H₂O + NO₂

Balance the equation and answer the following questions based on it.

(i) What mass of phosphoric acid can be prepared from 6.2 g of phosphorus?

(ii) What mass of nitric acid will be consumed at the same time ?

(iii) What would be the volume of steam produced at the same time if measured at 760 mm. Hg pressure and 273°C.

(Atomic wt of H = 1, N = 14, O = 16, P = 31) ?

Define

(i) Acid

(ii) molar volume

(iii) neutralisation.

(i) Define pH. If the hydrogen ion concentration of a solution is 10^-12 moles per litre, calculate its pH value.

(ii) What fluid is injected when yellow wasps or white ants bite? How can the pain be relieved?

(iii) A solution of Iron (III) chloride has a pH less than 7. Is the solution acidic or alkaline. Write the equation of its hydrolysis.

(iv) If iron is reacted with dilute sulphuric acid, what will be the product formed ?