For the reaction,
A (g) + 2B (g) → 2C (g) + 3D (g)
the change of enthalpy at 27°C is 19 kcal. The value of E is
21.2 kcal
17.8 kcal
18.4 kcal
20.6 kcal
Glucose is added to 1 L water to sch an extent that becomes equal to 10-3, the weight of glucose (C6H12O6 ) added is
180 gm
18 gm
1.8 gm
0.18 gm
Manganese salt + PbO2 + conc. HNO3 → the solution acquires purple colour. The colour is due to
Mn(NO3)2
Pb(NO3)2
HMnO4
MnO
One faraday of current was passed through the electrolytic cells placed in series containing solution of Ag+, Ni2+ and Cr3+ respectively. The ratio of amounts of Ag, Ni and Cr deposited will be
(atomic weigth of Ag = 108, Ni = 59 and Cr = 52)
108, 29.5, 17.4
17.4, 29.5, 108
1, 2, 3
108, 59, 52
In the extraction of copper, metal is formed is the Bessemer converter due to reaction
2Cu2S + 2Cu2O → 6Cu + SO2
2Cu2O → 4Cu + O2
Cu2S → 2Cu + S
Fe + Cu2O → 2Cu + FeO
Which are of the following is a false statement?
Cell fluid is an example of sol
Butter is an example of gel
Hair cream is an example of emulsion
Cheese is an example of foam
50 g of saturated aqueous solution of potassium chloride at 30°C is evaporated to dryness, when 13.2 gm of dry KCl was obtained. The solubility of KCl in water at 30°C is
35.87 g
25.62 g
28.97 g
27.81 g
Zinc is used to protect iron from corrosion because
Ered of An < Ered of iron
Eoxidation of Zn < Eoxidation of iron
Eoxidation of Zn = Eoxidation of iron
Zinc is cheaper than iron
At room temperature, the reaction between NO and O2 to give NO2 is fast while that of between CO and O2 is slow. It is because
the intrinsic energy of the reaction 2NO + O2 2NO2 is less
CO is smaller in size than that of NO
CO is poisonous
the activation energy for the reaction 2 NO + O2 2NO2 is less
A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3 g of the isotope in the container. Find the initial weight of the isotope, when it was packed (antilog 1.203 = 16)
12 gm
24 gm
36 gm
48 gm
D.
48 gm
No. of half-lives, n =
Amount left after n half-lives =