$A$ certain mass of a gas occupies a volume of $2 \ L$ at $STP$. To what temperature must the gas be heated to double its volume,keeping the pressure constant?

Steam at $100\,^{\circ}C$ is passed into $22\,g$ of water at $20\,^{\circ}C$. The mass of water that will be present when the water acquires a temperature of $90\,^{\circ}C$ (Latent heat of steam is $540\, cal/g$) is ............ $g$.

$y+x^2=\frac{dy}{dx}$ has the solution

Which one has the maximum oxidation number of phosphorus?

The solution of $\frac{dy}{dx} + \frac{1}{3}y = 1$ is

Two bodies of $6 \ kg$ and $4 \ kg$ masses have their velocities $5 \hat{i}-2 \hat{j}+10 \hat{k}$ and $10 \hat{i}-2 \hat{j}+5 \hat{k}$ respectively. Then the velocity of their centre of mass is