Qualitative and quantitative analysis

$10 \mathrm{mL}$ of hydrocarbon as exploded in excess of air. After cooling, there was a contraction in volume of $30 \mathrm{mL}$ and after treatment with $\mathrm{KOH}$, there was a further reduction of $30 \mathrm{mL}$. The formula of hydrocarbon is ${\mathrm{C}}_{\mathrm{x}}{\mathrm{H}}_{\mathrm{y}}$. The value of $\mathrm{x}+\mathrm{y}$ is 

Discuss the different types of test conducted for confirming radicals.

Define qualitative and quantitative analysis.

In Zeisel's method for the determination of methoxyl groups, a sample of 2.68 gm of a compound (A) gave 14.08 gm of AgI. If the molecular weight of compound (A) is 134, the number of (—OCH₃) group(s) in the compound (A) is:

Qualitative test of halogens in an organic compound is made by

An organic compound contains $\mathrm{N}$, $\mathrm{S}$, $\mathrm{C}$ and $\mathrm{H}$. Which of these is not used in quantitative detection of the organic compound?

Determine the value of percentage of nitrogen in the compound, when in Duma's method for the estimation of nitrogen $0.30 \mathrm{g}$ of organic compound gave $50 {\mathrm{cm}}^3$ of nitrogen gas collected at $300 \mathrm{K} \mathrm{and} 715 \mathrm{nm}$ pressure. Aqueous tension at $300 \mathrm{K}=15 \mathrm{mm} \mathrm{of} \mathrm{Hg}$.

$23.2 \mathrm{g}$ of an organic compound having molecular formula ${\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}+2}$ is burnt in excess of ${\mathrm{O}}_2\left(\mathrm{g}\right)$, initially taken in a $44.82 \mathrm{L}$ steel vessel. Before the reaction, the gaseous mixture was at $273 \mathrm{K}$ with a pressure of $2 \mathrm{atm}$. After complete combustion and loss of a considerable amount of heat, the mixture of product and excess of ${\mathrm{O}}_2$ had a temperature of $546 \mathrm{K}$ and $4.6 \mathrm{atm}$ pressure. The formula of the compound is

Three separate samples of a solution of a single salt gave these results. One formed a white precipitate with excess ammonia solution, one formed a white precipitate with dil. NaCl solution and one formed a black precipitate with H₂S. The salt could be :