251.

What weight of Ca will contain the same number of atoms as are present in 3.2g of sulphur?

0.01 mole of a compound weighs 1 g. Calculate the molecular mass of the compound.

Calculate the mass of 1 a.m.u in grams.

Calculate the number of atoms in each of the following;
(i) 52 moles of Ar 
(ii) 52 u of He
(iii) 52 g of He.

Which one of the following will have largest number of atoms?

• 1g Au (s)
• 1g Na (s)
• 1g Li (s)
• 1 g of Cl₂(g)

The cost of table salt (NaCl) is Rs 8 per kg. Calculate its cost per mole.

The molecular formula of a commercial resin used for exchanging ions in water softening is C₈H₇SO₃Na ( mol. wt = 206). What would be the maximum uptake of Ca²⁺ ions by the resin when expressed in mole per gram resin?

• 1/103

• 1/206

• 2/309

• 2/309

In Carius method of estimation of halogens, 250 mg of an organic compound gave 141 mg of AgBr. The percentage of bromine in the compound is: (at. Mass Ag = 108; Br = 80)

• 24

• 36

• 48

• 48

A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of CO₂.The empirical formula of the hydrocarbon is 

• C₂H₄

• C₃H₄

• C₆H₅

• C₆H₅