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)

How will you explain the law of constant proportions on the basis of Dalton's atomic theory?

3

(a)

The drawbacks of Dalton's atomic theory of matter.

3

(a)

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid.The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g sodium ethanoate.Show that these observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid \(\rightarrow \) sodium ethanoate + carbon dioxide + water

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(a)

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

3

(a)

What is the utility of the mole concept?

3

(a)

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

3

(a)

If the molar mass of carbon is 12g, what is the mass of one atom of carbon in 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)

The mass of a single atom M is 3.05 x 10^-23 g.What is its atomic weight?What would this element be? Check table for possible answers.

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)

Which amongest the following has more number of atoms, 11.5 g of sodium or 15 g of calcium?How?(Given atomic mass of Na =23, ca=40)

3

(a)

Which has more number of atoms, 100 grams of sodium or 100 grams of iron (Given, atomic mass of Na = 23 u, Fe = 56 u)?

3

(a)

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

3

(a)