In the cyanide extraction process of silver from argentite ore, the oxidising and reducing agents used are
Answer
(B)
O2 and Zn dust respectively
2
The electrochemical cell shown below is a concentration cell. M | M2+ (saturated solution of a sparingly soluble salt, MX2) || M2+ (0.001 mol dm–3) | M The emf of the cell depends on the difference in concentrations of M2+ ions at the two electrodes. The emf of the cell at 298 K is 0.059 V.
The value of ∆G (kJ mol–1) for the given cell is (take 1F = 96500 C mol–1)
Answer
(D)
-11.4
3
The electrochemical cell shown below is a concentration cell. M | M2+ (saturated solution of a sparingly soluble salt, MX2) || M2+ (0.001 mol dm–3) | M The emf of the cell depends on the difference in concentrations of M2+ ions at the two electrodes. The emf of the cell at 298 K is 0.059 V.
The solubility product (Ksp; mol3 dm–9) of MX2 at 298 K based on the information available for the given concentration cell is (take 2.303 $$\times$$ R $$\times$$ 298/F = 0.059 V)
Answer
(B)
4 $$\times$$ 10–15
4
For a dilute solution containing 2.5 g of a non-volatile non-electrolyte solute in 100 g of water. the elevation in boiling point at 1 atm pressure is 2oC. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure (mm of Hg) of the solution is (take Kb = 0.76 K Kg mol-1)
Answer
(A)
724
5
The major product H of the given reaction sequence is
$$C{H_3} - C{H_2} - CO - C{H_3}\buildrel {\overline C N} \over
\longrightarrow G\mathrel{\mathop{\kern0pt\longrightarrow}
\limits_{Heat}^{95\% \,{H_2}S{O_4}}} H$$
Answer
(A)
6
$$NiC{l_2}{\{ P{({C_2}{H_5})_2}({C_6}{H_5})\} _2}$$ exhibits temperature-dependent magnetic behaviour (paramagnetic/diamagnetic). The coordination geometries of Ni2+ in the paramagnetic and diamagnetic states are, respectively,
Answer
(C)
tetrahedral and square planar.
7
The reaction of white phosphorous with aqueous NaOH gives phosphine along with another phosphorus containing compound. The reaction type; the oxidation states of phosphorus in phosphine and the other product are, respectively,
Answer
(C)
disproportionation reaction; $$-$$3 and +1
8
The shape of XeO2F2 molecule is
Answer
(D)
see-saw.
9
The compound that undergoes decarboxylation most readily under mild condition is
Answer
(B)
10
Using the data provided, calculate the multiple bond energy (kJ mol$$-$$1) of a C=C bond in C2H2. That energy is (take the bond energy of C-H bond as 350 kJ mol$$-$$1).
Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is
Answer
(A)
Cl2O
14
25 mL of household bleach solution was mixed with 30 mL of 0.50 M KI and 10 mL of 4 N acetic acid. In the titration of the liberated iodine, 48 mL of 0.25 N Na2S2O3 was used to reach the end point. The molarity of the household bleach solution is
Answer
(C)
0.24 M
15
The reversible expansion of an ideal gas under adiabatic and isothermal conditions is shown in the figure. Which of the following statement(s) is(are) correct?
Answer
A
D
16
For the given aqueous reactions, which of the statement(s) is(are) true?
Answer
A
C
D
17
With reference to the scheme given, which of the given statement(s) about T, U, V and W is(are) correct?
Answer
A
C
D
18
Which of the given statement(s) about N, O, P and Q with respect to M is(are) correct?
Answer
A
B
C
19
With respect to graphite and diamond, which of the statement(s) given below is(are) correct?
Answer
B
D
20
The given graphs/data I, II, III and IV represent general trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure. Which of the following choice(s) about I, II, III and IV is(are) correct?