Some Basic Conc...

To convert molality into which of the following unit of concentration require density of the solution?

25.5g of $$H_{2}O_{2}$$ solution on decomposition gave 1.68L of $$O_{2}$$ at STP. The percentage strength by weight of the solution is:

$$100$$gm of an aq. solution of sugar contains $$40\%$$ sugar by mass. How much water should be evaporated get $$50\%$$ sugar solution by mass?

According to percentage weight arrange the following in descending order in the earth crust ?

Calculate the mass percent of carbon in $${ C }_{ 2 }H_{ 5 }OH$$ (Molar mass of ethanol=46.068g)

One mole sample of $$FeO$$ is heated in air until it is completely converted into $$Fe_2O_3$$. The percentage increase in weight of the sample is?

Aqueous urea solution is 20% by mass of solution. Calculate percentage by mass of solvent.

A gaseous mixture contains $$CH_4$$ and $$C_2H_6$$ in equimolecular proportion. The weight of 2.27 litres of this mixture at STP is:

Which of the following is the best example of law of conservation of mass?

$$27\ gm\ Al$$ is heated with $$49\ ml$$ of $$H_{2}SO_{4}$$ (specific gravity $$=2$$) produces $$H_{2}$$ gas. Percentage of $$Al$$ reacted with $$H_{2}SO_{4}$$ is: