(i) Inorganic compound `'A' (aq) + "DeVarda's alloy" overset(Delta)rarr B (g) + "salt" `
(ii) `'A'(aq) + C overset(Delta)rarr PH_(3) (g)`,
(iii) `A (aq) + NH_(4)Cl overset(Delta)rarr D (g) + Cl^(-) +H_(2)O`,
(iv) B is colourless combustible lightest gas.
(v) D-truns red litmus blue.
Which of the following combination is correct ?

Options

A. `A = KOH`
`B = H_(2)`
`C = H_(3)PO_(3)`
`D = NH_(3)`
B. `A = NaOH`
`B = H_(2)`
`C = H_(3)PO_(4)`
`D = PH_(3)`
C. `A = NaOH`
`B = H_(2)`
`C = H_(3)PO_(4)`
`D = NH_(3)`
D. `A = NaOH`
`B = H_(2)`
`C = P_(4)`
`D = NH_(3)`

Answer

D

Explanation

Devarda's alloy contains `Al, Zn` & `Cu`
`underset((A))(NaOH) + Al overset(Delta)rarr NaAlO_(2) + underset((B))(H_(2) (g))`,
`underset((A))(NaOH) + Zn overset(Delta)rarr Na_(2)ZnO_(2)+ underset((B))(H_(2)(g))`,
`underset((A))(NaOH) + P_(4) overset(Delta)rarr NaH_(2)PO_(2) + PH_(3) (g)`,
`underset((A))(NaOH) + NH_(4)Cl overset(Delta)rarr underset((D))(NH_(3)) + NaCl + H_(2)O`,