Amongst the following, which liquids are taken in nitrometer in Dumas method?

$0.5264 \mathrm{g}$ of silver bromide is obtained from $0.5124 \mathrm{g}$ of an organic compound. The percentage of bromine in the compound is

In Kjeldahl's method, ammonia from $5 \mathrm{g}$ of food neutralizes $30 \mathrm{mL}$of $0.1 \mathrm{N}$ acid. The percentage of nitrogen in the food is:

$0.24 \mathrm{g}$ of an organic compound gives $0.22 \mathrm{g} {\mathrm{CO}}_2$ on complete combustion. If it contains $16.6\%$ hydrogen, the percentage of carbon and oxygen, respectively are:

What is the order of basicity of the following compounds?

Deduce the best place to protonate in the following :