Long Answer TypeWhat weight of Ca will contain the same number of atoms as are present in 3.2g of sulphur?
Short Answer TypeCalculate the number of atoms in each of the following;
(i) 52 moles of Ar
(ii) 52 u of He
(iii) 52 g of He.
Multiple Choice QuestionsWhich one of the following will have largest number of atoms?
Short Answer TypeMultiple Choice QuestionsThe 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
D.
2/309
We know the molecular weight of C8H7SO3Na
= 12x8+1x7+32+16x3+23 = 206
we have to find mole per gram of resin
therefore,
1 g of C8H7SO3Na has number of mole
=1/206 mol
Taking the reaction,
C8H7SO3Na + Ca2+ → (C6H7SO3)2Ca + 2Na+
therefore, 2 moles of C8H7SO3Na combines with 1 mol of Ca2+
Thus, 1 mole of C8H7SO3Na will combine with 0.5 mol of Ca2+
Hence, 1/206 mole of C8H7SO3Na will combine with,
0.5 x (1/206)mol of Ca2+ = 1/412 mol Ca2+
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
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