Questions in chemical-aritmatic

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	If the density of water is 1 g $c{m^{ - 3}}$ then the volume occupied by one molecule of water is approximately
	Caffeine has a molecular weight of 194. If it contains 28.9% by mass of nitrogen, number of atoms of nitrogen in one molecule of caffeine is
	A 400 mg iron capsule contains 100 mg of ferrous fumarate, ${(CHCOO)_2}Fe$. The percentage of iron pasent in it is approximately
	The element whose a atom has mass of $10.86 \times {10^{ - 26}}$kg is
	The number of gram atoms of oxygen present in 0.3 gram mole of ${(COOH)_2}.2{H_2}O$is
	A gaseous mixture contains $C{H_4}$and ${C_2}{H_6}$in equimolecular proportion. The weight of 2.24 litres of this mixture at NTP is
	Vapour density of a metal chloride is 66. Its oxide contains 53% metal. The atomic weight of the metal is
	One gram of hydrogen is found to combine with 80g of bromine one gram of calcium valency=2 combines with 4g of bromine the equivalent weight of calcium is
	The equivalent weight of $MnS{O_4}$is half its molecular weight when it is converted to
	$100\;mL$ of $P{H_3}$ on decomposition produced phosphorus and hydrogen. The change in volume is