Problem 29
\(25 \mathrm{ml}\) of a solution of barium hydroxide on titration with \(0.1\) molar solution of hydrochloric acid gave a titre value of \(35 \mathrm{ml}\). The molarity of barium hydroxide solution was a. \(0.07\) b. \(0.14\) c. \(0.28\) d. \(0.35\)
Problem 30
A compound has haemoglobin like structure. It has one Fe. It contain \(4.6 \%\) of Fe. The approximate molecular mass is a. \(1400 \mathrm{~g} \mathrm{~mol}^{-1}\) b. \(1000 \mathrm{~g} \mathrm{~mol}^{-1}\) c. \(1100 \mathrm{~g} \mathrm{~mol}^{-1}\) d. \(1200 \mathrm{~g} \mathrm{~mol}^{-1}\)
Problem 31
The maximum number of molecules is present in a. \(15 \mathrm{~L}\) of \(\mathrm{H}_{2}\) gas at STP b. \(5 \mathrm{~L}\) of \(\mathrm{N}_{2}\) gas at STP c. \(0.5 \mathrm{~g}\) of \(\mathrm{H}_{2}\) gas d. \(10 \mathrm{~g}\) of \(\mathrm{O}_{2}\) gas
Problem 32
To neutralize completely \(20 \mathrm{ml}\) of \(0.1 \mathrm{M}\) aqueous solution of phosphorus acid, the volume of \(0.1 \mathrm{M}\) aqueous KOH solution required is a. \(10 \mathrm{ml}\) b. \(40 \mathrm{ml}\) c. \(60 \mathrm{ml}\) d. \(80 \mathrm{ml}\)
Problem 33
\(6.02 \times 10^{20}\) molecules of urea are present in 100 mlof its solution. The concentration of urea solution isa. \(0.02 \mathrm{M}\) b. \(0.001 \mathrm{M}\) c. \(0.01 \mathrm{M}\) d. \(0.1 \mathrm{M}\)
Problem 35
An organic compound containing \(\mathrm{C}\) and \(\mathrm{H}\) has \(92.3 \%\) of carbon. Its empirical formula is a. \(\mathrm{CH}_{4}\) b. \(\mathrm{CH}_{3}\) c. \(\mathrm{CH}_{2}\) d. \(\mathrm{CH}\)
Problem 36
\(4 \mathrm{~g}\) of copper was dissolved in concentrated nitric acid. The copper nitrate on strong heating gave \(5 \mathrm{~g}\) of its oxide. The equivalent weight of copper is a. 12 b. 16 c. 32 d. 34
Problem 37
A gas mixture contains \(50 \%\) helium and \(50 \%\) methane by volume. What is the per cent by weight of methane in the mixture? a. \(83 \%\) b. \(73.0 \%\) c. \(18.01 \%\) d. \(80.0 \%\) e. \(90.1 \%\)
Problem 38
Number of water molecules in the drop of water, if \(1 \mathrm{ml}\) of water has 20 drops and 'A' is Avogadro's number, is a. \(0.5 \mathrm{~A}\) b. \(0.5 \mathrm{~A} / 18\) c. \(0.05 \mathrm{~A} / 18\) d. \(0.05 \mathrm{~A}\)
Problem 41
An alkaloid contains \(17.28 \%\) of nitrogen and its molecular mass is \(162 .\) The number of nitrogen atoms present in one molecule of the alkaloid isa. One b. Two c. Three d. Four e. Five
