Multiple Choice Questions200 mL of an aqueous solution of a protein contains its 1.26 g . The osmotic pressure of this solution at 300 K is found to be 2.57 x 10-3 bar. The molar mass of protein will be (R = 0.083 L bar mol-1 K-1)
51022 g mol-1
122044 g mol-1
31011 g mol-1
31011 g mol-1
D.
31011 g mol-1
In qualitative analysis, the metals of group I can be separted from other ions by precipitating them as chloride salts. A solution initially contains Ag+ and Pb2+ at a concentration of 0.10 M. Aqueous HCl is added to this solution until the Cl- concentration is 0.10 M. What will be the concentration of Ag+ and Pb2+ be at equilibrium? (Ksp for AgCl = 1.8 x 10-10, Ksp for PbCl2 = 1.7 x 10-5)
[Ag+] = 1.8 x 10-7 M; [Pb2+] = 1.7 x 10-6 M
[Ag+] = 1.8 x 10-11 M; [Pb2+] = 8.5 x 10-5 M
[Ag+] = 1.8 x 10-9 M; [Pb2+] = 1.7 x 10-3 M
[Ag+] = 1.8 x 10-9 M; [Pb2+] = 1.7 x 10-3 M
C.
[Ag+] = 1.8 x 10-9 M; [Pb2+] = 1.7 x 10-3 M
The pair of species of oxygen and their magnetic behaviours are noted below. Which of the following presents the correct description?
C.
As O2+, O2, O2-, O and O+ have unpaired electrons, hence are paramagnetic. The species which have unpaired electrons has paramagnetic behaviour.
A solution contains Fe2+ Fe3+, and I- ions. This solution was treated with iodine at 35o C.Eo for Fe3+/ Fe2+ is +0.77 V and Eo for I2/ 2 I- = 0.536 V. The favourable redox reaction is
I2 will be reduced to I-
There will be No redox reaction
I- will be oxidised to I2
I- will be oxidised to I2
C.
I- will be oxidised to I2
The rate of reaction 2N2O3 → 4 NO2 + O2 can be written in three ways
The relationship between k and k' and between k and k'' are
k' = 2k ; k' = k
k' = 2k; k" = k/2
k' = 2k; k' = 2k
k' = 2k; k' = 2k
B.
k' = 2k; k" = k/2
The unit of rate constant for a zero order reaction is
mol L-1 s-1
L mol-1 s-1
L2 mol-2 s-1
L2 mol-2 s-1
B.
L mol-1 s-1
For zero order reaction,
Rate = k [ reaction]o
therefore, Rate = k
and unit of k = mol L- s-1
Which of the following carbonyl will have the strongest C- O bond?
(Mn(CO)6+
Cr(CO)6
V (CO)6-
V (CO)6-
A.
(Mn(CO)6+
As the positive charge on the central metal atom increase, the less readily the metal can donate electron density into the anti - bonding pi-orbitals of CO ligand to weaken the C-O bond. Hence, the C-O bond would be strongest in Mn(CO)6+.
The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of the slag.
Fe2O3 (s) + 3CO (g) → 2 Fe (l) +3CO2 (g)
CaCO3 (s) → CaO (s) + CO2 (g)
CaO (s) +SiO2 → CaSiO3 (s)
CaO (s) +SiO2 → CaSiO3 (s)
C.
CaO (s) +SiO2 → CaSiO3 (s)
A slag is an easily fusible material which is formed when gangue still present in the roasted or the calcined ore combines with the flux. For example, in the metallurgy of iron, CaO (flux) combines with silica gangue to form easily fusible calcium silicate (CaSiO3) slag.
CaO + SiO2 → CaSiO3 (slag)
Which of the following oxide is amphoteric?
SnO2
CaO2
SiO2
SiO2
A.
SnO2
SnO2 is an amphoteric oxide because it reacts with acids as well as bases to form corresponding salts.
SnO2 +4HCl → SnCl4 +2H2O
SnO2 + 2 NaOH → Na2SnO3 + H2O
A solid compound XY has NaCl structure. If the radius of the cation is 100 pm, the radius of the anion (Y-) will be
275.1 pm
322.5 pm
241.5 pm
241.5 pm
C.
241.5 pm
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