34
MCQ (Multiple Correct Answer)
Which of the following orders are correct as per the properties mentioned against each?
A
$\mathrm{As}_2 \mathrm{O}_3<\mathrm{SiO}_2<\mathrm{P}_2 \mathrm{O}_3<\mathrm{SO}_2\quad$ Acid strength.
B
$\mathrm{AsH}_3<\mathrm{PH}_3<\mathrm{NH}_3\quad$ Enthalpy of vaporisation.
C
$\mathrm{S}<\mathrm{O}<\mathrm{Cl}<\mathrm{F}\quad$ More negative electron gain enthalpy.
D
$\mathrm{H}_2 \mathrm{O}>\mathrm{H}_2 \mathrm{~S}>\mathrm{H}_2 \mathrm{Se}>\mathrm{H}_2 \mathrm{Te}\quad$ Thermal stability.
35
MCQ (Multiple Correct Answer)
Which of the following statements are correct?
A
$\mathrm{S}-\mathrm{S}$ bond is present in $\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_6$
B
In peroxosulphuric acid $\left(\mathrm{H}_2 \mathrm{SO}_5\right)$ sulphur is in +6 oxidation state
C
Iron powder along with $\mathrm{Al}_2 \mathrm{O}_3$ and $\mathrm{K}_2 \mathrm{O}$ is used as a catalyst in the preparation of $\mathrm{NH}_3$ by Haber's process
D
Change in enthalpy is positive for the preparation of $\mathrm{SO}_3$ by catalytic oxidation of $\mathrm{SO}_2$
36
MCQ (Multiple Correct Answer)
In which of the following reactions conc. $\mathrm{H}_2 \mathrm{SO}_4$ is used as an oxidising reagent?
A
$\mathrm{CaF}_2+\mathrm{H}_2 \mathrm{SO}_4 \longrightarrow \mathrm{CaSO}_4+2 \mathrm{HF}$
B
$2 \mathrm{HI}+\mathrm{H}_2 \mathrm{SO}_4 \longrightarrow \mathrm{I}_2+\mathrm{SO}_2+2 \mathrm{H}_2 \mathrm{O}$
C
$\mathrm{Cu}+2 \mathrm{H}_2 \mathrm{SO}_4 \longrightarrow \mathrm{CuSO}_4+\mathrm{SO}_2+2 \mathrm{H}_2 \mathrm{O}$
D
$\mathrm{NaCl}+\mathrm{H}_2 \mathrm{SO}_4 \longrightarrow \mathrm{NaHSO}_4+\mathrm{HCl}$
37
MCQ (Multiple Correct Answer)
Which of the following statements are true?
A
Only type of interactions between particles of noble gases are due to weak dispersion forces.
B
Ionisation enthalpy of molecular oxygen is very close to that of xenon.
C
Hydrolysis of $\mathrm{XeF}_6$ is a redox reaction.
D
Xenon fluorides are not reactive.
38
Subjective
In the preparation of $\mathrm{H}_2 \mathrm{SO}_4$ by Contact process, why is $\mathrm{SO}_3$ not absorbed directly in water to form $\mathrm{H}_2 \mathrm{SO}_4$ ?
Explanation
In Contact process $\mathrm{SO}_3$ is not absorbed directly in water to from $\mathrm{H}_2 \mathrm{SO}_4$ because the reaction is highly exothermic, acid mist is formed. Hence, the reaction becomes difficult to handle.
Note
