Questions in chemical-aritmatic

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	On reduction with hydrogen, 3.6 g of an oxide of metal left 3.2 g of metal. If the vapour density of metal is 32, the simplest formula of the oxide would be
	The number of molecules in 4.25 g of ammonia are
	Which one of the following pairs of gases contains the same number of molecules
	Number of gm of oxygen in 32.2 g $N{a_2}S{O_4}.10{H_2}O$is
	250 ml of a sodium carbonate solution contains 2.65 grams of $N{a_2}C{O_3}$. If 10 ml of this solution is diluted to one litre, what is the concentration of the resultant solution (mol. wt. of $N{a_2}C{O_3}$=106)
	A molar solution is one that contains one mole of a solute in
	The number of oxygen atoms in 4.4 g of $C{O_2}$is approx.
	The volume occupied by 4.4 g of $C{O_2}$at STP is
	The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is
	One mole of calcium phosphide on reaction with excess of water gives