The number of oxygen atoms in a solution prepared by dissolving $34.2 \ g$ of sucrose in $90 \ g$ of water is:

Assume that a human body requires $2500 \, kcal$ of energy each day for metabolic activity and sucrose is the only source of energy,as per the equation $C_{12}H_{22}O_{11(s)} + 12 \, O_{2(g)} \longrightarrow 12 \, CO_{2(g)} + 11 \, H_2O_{(l)};$ $\Delta H = -5.6 \times 10^6 \, J$. (Fill in the blanks) $(a)$ The energy requirement of the human body per day is $.... \, kJ$. $(b)$ The mass of sucrose required to provide this energy is $........ \, g$ and the volume of $CO_2$ (at $STP$) produced is $......... \, litres.$

When a jar containing a gaseous mixture of equal volumes of $CO_2$ and $H_2$ is placed in a solution of sodium hydroxide,the solution level will:

$A$ metal oxide contains $75 \%$ metal by mass. If the vapour density of the metal chloride is $89$,what is the atomic weight of the metal?

Which one of the following is the lightest?

Ferric alum has the composition $(NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot xH_2O$,where $x$ is..........