The same mass of $CH_4$ and $H_2$ is taken in a container. The partial pressure caused by $H_2$ is:

Diatoms,microscopic organisms,are an abundant food source in the oceans producing carbohydrates from carbon dioxide and water by photosynthesis.
$6CO_2 + 6H_2O + \text{solar energy} \to C_6H_{12}O_6 + 6O_2$
$A$ blue whale gains $75 kg$ of mass per day by feeding on krill. The whale must consume ten times this mass of krill each day. The krill must consume $10.0 kg$ of diatoms to produce $1.0 kg$ of krill. Assuming that the mass gain of a whale's life is due to the consumption of carbohydrates $(C_6H_{12}O_6)$,calculate the moles of $CO_2$ that must be used by the diatoms to produce the carbohydrates consumed by a blue whale in a day.

How many $mL$ of $0.1\, M\, HCl$ are required to react completely with $1\, g$ mixture of $Na_2CO_3$ and $NaHCO_3$ containing equimolar amounts of both?

If $10$ volumes of dihydrogen gas react with $5$ volumes of dioxygen gas, how many volumes of water vapour would be produced?

What is the mass of potassium chloride produced when $12.25 \ g$ of potassium chlorate undergoes decomposition (in $g$)? (Atomic masses: $K=39, Cl=35.5, O=16$)

How many grams of concentrated nitric acid solution should be used to prepare $250 \ mL$ of $2.0 \ M \ HNO_3$? The concentrated acid is $70\% \ HNO_3$ by mass.