Give below are two statements:
Statement - I: Noble gases have very high boiling points.
Statement - II: Noble gases are monoatomic gases. They are held together by strong dispersion forces. Because of this they are liquefied at very low temperature. Hence, they have very high boiling points.
In the light of the above statements, choose the correct answer from the options given below:
A and B formed in the following reactions are:
$$\begin{aligned} & \mathrm{CrO}_2 \mathrm{Cl}_2+4 \mathrm{NaOH} \rightarrow \mathrm{A}+2 \mathrm{NaCl}+2 \mathrm{H}_2 \mathrm{O}, \\ & \mathrm{A}+2 \mathrm{HCl}+2 \mathrm{H}_2 \mathrm{O}_2 \rightarrow \mathrm{B}+3 \mathrm{H}_2 \mathrm{O} \end{aligned}$$
Choose the correct statements about the hydrides of group 15 elements.
A. The stability of the hydrides decreases in the order $$\mathrm{NH}_3>\mathrm{PH}_3>\mathrm{AsH}_3> \mathrm{SbH}_3>\mathrm{BiH}_3$$.
B. The reducing ability of the hydride increases in the order $$\mathrm{NH}_3<\mathrm{PH}_3<\mathrm{AsH}_3 <\mathrm{SbH}_3<\mathrm{BiH}_3$$.
C. Among the hydrides, $$\mathrm{NH}_3$$ is strong reducing agent while $$\mathrm{BiH}_3$$ is mild reducing agent.
D. The basicity of the hydrides increases in the order $$\mathrm{NH}_3<\mathrm{PH}_3<\mathrm{AsH}_3< \mathrm{SbH}_3<\mathrm{BiH}_3$$.
Choose the most appropriate from the options given below :
Given below are two statements :
Statement (I) : The gas liberated on warming a salt with dil $$\mathrm{H}_2 \mathrm{SO}_4$$, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.
Statement (II) : In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below :