The activation energy for a reaction is $9.0 \mathrm{~K} \mathrm{cal} \mathrm{mol}^{-1}$. The increase in the rate constant when its temperature is increased from 298 K to 308 K is
4.5 g of aluminium (Atomic mass 27 amu ) is deposited at cathode from $\mathrm{Al}^{3+}$ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from $\mathrm{H}^{+}$ions in the solution by the same quantity of electric charge will be
When diluted $\mathrm{H}_2 \mathrm{SO}_4$ is added to aqueous solution of potassium chromate, yellow colour solution turns to orange colour. This signifies that
How long should water be electrolysed by passing through 100 amperes current so that oxygen released can completely burn 27.66 g of diborane? (Weight of $B=10.8 \mathrm{u}$ )