Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?
NaOCl
NaClO3
NaClO2
NaClO4
Helium mixed with oxygen is used in the treatment of
beri beri
burning feet
joints burning
asthma
Which of the following is a correct statement?
Aqueous solutions of Cu+ and Zn2+ are colourless
Aqueous solutions of Cu2+ and Zn2+ are colourless
Aqueous solution of Fe3+ is green in colour
Aqueous solution of MnO-4 is colourless
The chemical reaction that involves roasting process is
Fe2O3 + 3CO → 2Fe + 3CO2
2Al + Fe2O3 → 2Fe + Al2O3
2ZnS + 3O2 → 2ZnO + 3SO2
FeO + SiO2 → FeSiO3
The ratio of anion radius to cation radius of a crystal is 10 : 9.3. Then, the coordination number of the cation in the crystal is
2
6
4
8
If BaCl2,ionizes to an extent of 80% in aqueous solution, the value of van't Hoff factor is
2.6
0.4
0.8
2.4
X is a non-volatile solute and Y is a volatile solvent. The following vapour pressures are observed by dissolving X in Y.
X/mol L-1 | Y/mm of Hg |
0.10 | p1 |
0.25 | p2 |
0.01 | p3 |
The correct order of vapour pressures is
p1 < p2 <p3
p3 < p2 < p1
p3 <p1 < p2
p2 <p1 <p3
D.
p2 <p1 <p3
When a non-volatile solute is added to a volatile solvent, the solute covers up some of the surface of solvent. Thus, less surface area is available for vaporisation of solvent and hence,
vapour pressure decreases. As the amount of non-volatile solute increases, vapour pressure
decreases accordingly.
The order of concentration of X is
0.01 < 0.10 < 0.25
The order of vapour pressure is
p2 <p1 <p3
At a certain temperature and at infinite dilution, the equivalent conductances of sodium benzoate, hydrochloric acid and sodium chlonde are 240, 349 and 229 ohm-1 cm2equiv-1 respectively. The equivalent conductance of benzoic acid in ohm-1 cm2equiv-1 at the same conditions is
80
328
360
408