50 g 0f 10% lead nitrate is mixed with 50g of 10% sodium chloride in a closed vessel.After reaction has taken place, it was found that 6.83 g of lead chloride was precipated.Besides, the reaction mixture contained 90g water and sodium nitrate.Calculate the amount of sodium nitrate formed. 

3

(a)

The drawbacks of Dalton's atomic theory of matter.

3

(a)

Give an account of existence of various elements and compounds.

3

(a)

Give the symbol and valency of the following polyatomic ions:
Ammonium, hydroxide, nitrate, carbonate, sulphate, sulphite, bicarbonate, phosphate.

3

(a)

Atomic mass of C-12 is 12 u.On the basis of mole concept, express 1 u into gram.

3

(a)

Calculate the following quantities in 5.6 g of nitrogen:(Atomic mass of N = 14u)
(a) Number of moles of N₂
(b) Number of molecules of N₂
Number of atoms of nitrogen

3

(a)

(a) Name a green house gas with molar mass 14g/mol and is known to extinguish fire.
(b) Name the elements present in this gas and write their valency
(c) Calculate the number of moles in 360 g of this gas sample
(d) Calculate the number of molecules in 88 g of this gas sample
(Given atomic mass of C =12u, O = 16u, No=6.022 x 10²³ per mole)

3

(a)

How many grames of Na will have the same number of atoms as in 6 grames of Mg?(Atomic mass Na=23.0u, Mg=24.0u)

3

(a)

Calculate the molecular masses of H₂, O₂, Cl₂, CO₂, CH₄, C₂H₆, NH₃, CH₃OH

3

(a)

Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.(Atomic mass of Al = 27u)

3

(a)