Mixtures and Alligation

Pehal and Ishaan were making $100g$ sugar solution with concentration by mass $20\%$ and $50\%$ respectively. Pehal added $20 g$ of sugar in her solution whereas ishaan evaporated $20 g$ of water from his solution. Now, the solutions were mixed to form a final solution, The concentration by mass of final solution is:

A gaseous mixture contains ${ CH }{ 4 }$ and ${ CH }{ 2 }{ H }_{ 6 }$ in equimolecular proportion. The weight of $2.24$ liters of this mixture at NTP is:

Vapour density of the equilibrium mixture of ${ NO }{ 2 }$ and ${ N }{ 2 }{ O }{ 4 }$ is found to be 40 for the equilibrium: ${ N }{ 2 }{ O }{ 4 }\rightleftharpoons 2{ NO }{ 2 }$. Calculate the percentage of ${ NO }_{ 2 }$ in the mixture?

300 gm of 25% w/w solution of solute A is mixed with 400 gm of 40 (w/w) solution of another solute B. What is the w/w percentage of new mixture.

A certain mixture of $MnO$ and $MNO_2$ contains $66.6\ mol$ per cent of $MnO_2$. What is the approximate mass percent of $Mn$ in it? $(Mn=55)$

Under the same conditions of temperature and pressure, 1 l of oxygen gas was mixed 1 l of carbon dioxide gas. The mass ration of the gases in the mixture will be:

When $3$ L of $0.5$ $M$ $\displaystyle NaCl$ is mixed with $9$ L of $0.2777$ $M$ $\displaystyle NaCl$, determine the concentration of the final solution, assuming that volumes are additive?

If you mix 3 litres of 0.5M $NaCl$ with 9 litres of 0.2777 M $NaCl$ what will the concentration of the final solution be, assuming that volumes are additive?

A mixture contains equimolar quantities of carbonates of two bivalent metals. One metal is present to the extent of $13.5\%$ by weight in the mixture and $2.58$g of the mixture on heating leaves a residue of $1.35$g. What percentage by weight of the other metal is there?

Find out the volume of $98\%$ (w/w) $\displaystyle H_{2}SO_{4}$ (density $= 1.8$ g/ml) that must be diluted to prepare $12.0$ litres of $2.4\; M$ sulphuric acid solution.

By the reaction of carbon and oxygen, a mixture of $CO$ and $CO_{2}$ is obtained. The mass ratio of the mixture obtained when $20$ g of $O_{2}$ reacts completely with $12$ g of carbon is: