Some Basic Conc...

$$10\ g$$ of a crystalline metal sulphate salt when heated generates approximately $$6.4\ g$$ of an anhydrous salt of the same metal. The molecular weight of the anhydrous salt is $$160\ g$$. The number of water molecules present in the crystal is

3 g of a hydrocarbon on combustion in excess of oxygen produces 8.8 g of $$CO_2$$ and 5.4 g of $$H_2O$$. 

Temporary hardness is due to bicarbonates of $$Mg^{2+}\, and\, Ca^{2+}$$, it is removed by addition of CaO as follows:
$$Ca(HCO_3)_2\,+\, CaO\, \rightarrow\, 2CaCO_3\,+\, H_2O$$
Mass of $$CaO$$ required to precipitate 2 g $$CaCO_3$$ is:

$$3.01\times 10^{23}$$ molecules of elemental Sulphur will react with 0.5 mole of oxygen gas completely to produce

A compound was found to contain 5.37% nitrogen. What is the minimum molecular weight of compound ?

Aluminium reduces manganese dioxide to manganese at high temperature. The amount of aluminium required to reduce one gram mole of manganese dioxide is

The volume of $$0.5 M$$ aqueous $$NaOH$$ solution required to neutralize $$10 ml$$ of $$2 M$$ aqueous $$HCl$$ solution is

Four 1-1 litre flasks are separately filled with the gases $$H_2,\, He,\, O_2$$ and ozone. The ratio of total number of atoms of these gases present in different flask would be : 

Number of moles of 1 $$m^3$$ gas, at STP, are:

Which law stated that 'matter is neither created nor destroyed'?