Multiple Choice Questions20 mL solution of 0.1 M ferrous sulphate was completely oxidised using a suitable oxidising agent. What is the number of electrons exchanged?
1.204 x 1022
193
1930
1.204 x 1021
The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na ( mol. wt = 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin?
1/103
1/206
2/309
2/309
In Carius method of estimation of halogens, 250 mg of an organic compound gave 141 mg of AgBr. The percentage of bromine in the compound is: (at. Mass Ag = 108; Br = 80)
24
36
48
48
A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of CO2.The empirical formula of the hydrocarbon is
C2H4
C3H4
C6H5
C6H5
Experimentally it was found that a metal oxide has formula M0.98O. Metal M, is present as M2+ and M3+ in its oxide. The fraction of the metal which exists as M3+ would be:
7.01%
4.08%
6.05%
6.05%
The most abundant element by mass in the body of a healthy human adult are :
Oxygen (61.4%) ; Carbon (22.9%), Hydrogen(10.0%) ; and Nitrogen (2.6%). The weight which a 75 kg person would gain if all 1H atoms are replaced by 2H atoms is
15 kg
37.5 Kg
7.5 Kg
7.5 Kg
How many moles of magnesium phosphate, Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?
0.02
3.125 × 10–2
1.25 × 10–2
1.25 × 10–2
If we consider that 1/6 in place of 1/12 mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will
Decrease twice
Increase two fold
Remain unchanged
Remain unchanged
The ratio of mass percent of C and H of an organic compound (CXHYOZ) is 6: 1. If one molecule of the above compound (CXHYOZ) contains half as much oxygen as required to burn one molecule of compound CXHY completely to CO2 and H2O. The empirical formula of compound CXHYOZ is
C2H4O3
C3H6O3
C2H4O
C3H4O2
0.126 g of an acid is needed to completely neutralise 20 mL 0.1 (N) NaOH solution. The equivalent weight of the acid is
53
40
45
63
