Hydrides of Phosphorus

Q. Which metal is the most reactive?

1. $Hg$
2. $Ag$
3. $Al$
4. $Mg$

Q. As we move down the group 15, the reducing nature of the hydrides

1. remains the same.
2. decreases.
3. increases
4. Increases first and then decreases.

Q. As we move down the group 15, the reducing nature of the hydrides

1. remains the same.
2. decreases.
3. increases
4. Increases first and then decreases.

Q. (12) Give reason
H₂Te is the strongest reducing agent amongst all the hydrides of Group 16 elements.

Q. Phosphorus cannot form $P{H}_5$ with its outer electronic configuration as $3s^{2}3p^3$ because:

1. $P{H}_5$ is not a stable compound
2. ${\Delta }_a$H value of dihydrogen and ${\Delta }_{eg}H$ value of hydrogen do not favor higher oxidation state of phosphorus
3. Phosphorus can not show + 5 oxidation state
4. Phosphorus is not very reactive

Q. There are some deposits of nitrates and phosphates in earth's crust. Nitrates are more soluble in water. Nitrates are difficult to reduce under the laboratory conditions but microbes do it easily. Ammonia forms large number of complexes with transition metal ions. Hybridisation easily explains the case of sigma donation capability of $N{H}_3$ and $P{H}_3$. Phosphine is a flammable gas and is prepared from white phosphorus.

Which phosphorous on reaction with NaOH gives $P{H}_3$ as one of the product. This is a

1. dimerisation reaction
2. disproportionation reaction
3. condensation reaction
4. precipitation reaction

Q. A buffer solution $0.04M$ in $N{a}_{2}HP{O}_4$ and $0.02M$ in $N{a}_{3}P{O}_4$ is prepared. The electrolytic oxidation of $1.0$ milli-mole of the organic compound $RNHOH$ is carried out in $100mL$ of the buffer. The reaction is
$RNHOH+H_{2}O⟶RN{O}_2+4H_4^{+}{e}^{-}$
The approximate $pH$ of solution after the oxidation is complete is:
[Given: for $H_{3}P{O}_4,p{K}_{a_1}=2.2;p{K}_{a_2}=7.2;p{K}_{a_3}=12$]

1. $6.90$
2. $7.20$
3. $7.5$
4. None of these

Q. $\left(CN{)}_2\right(g)+2O{H}^{-}(aq)\to \text{Products}$ are:

1. $C{N}^{-}$
2. $CN{O}^{-}$
3. $H_{2}O$
4. All are correct

Q. The most reactive form of phosphorus is :

1. yellow phosphorus
2. red phosphorus
3. violet phosphorus
4. black phosphorus

Q. How many species out of the following have reducing properties?

Q. Which of the following name is impossible?

1. Barium tetrafluoridobromate(III)
2. Dichlorobis(urea) copper(II)
3. Potassium tetrafluoridooxidochromate(VI)
4. All are impossible

Q. Which of the following metals is lightest and which one of them is least reactive?
$Cu,Ag,Al,Fe$

Q. Select the odd one out and justify your answer
$Fe,Zn,Cu$ and $Mg$

Q. Zinc is used for the recovery of Ag from the complex $\left[Ag\right(CN{)}_2]-$ while copper is not used because Zn is powerful reducing agent than Cu.
If true enter 1, else enter 0.