The correct increasing order of the acidity of is
(1)
(2)
(3)
(4)
At absolute zero.
(1) Only para hydrogen exists
(2) Only ortho hydrogen exists
(3) Both para and ortho hydrogen exist
(4) None of these
Metal which does not react with cold water but evolves H2 with steam is –
(1) Na
(2) K
(3) Pt
(4) Fe
The oxidation states of the most electronegative element in the products of the reaction between with dil. are–
1. 0, and –1
2. –1, and –2
3. –2, and 0
4. –2, and + 1
Hardness of water is due to presence of salts of –
(1)
(2)
(3)
(4)
Ice melts at a temperature lower than its usual melting point when the pressure is increased. This is because-
1. Ice has less density than water
2. Pressure generates heat
3. The chemical bonds break under pressure
4. Ice is not a true solid
An ionic compound is dissolved simultaneously in heavy water and ordinary water, its solubility is –
1. Larger in heavy water
2. Smaller in heavy water
3. Solubility is same in both waters
4. Smaller in simple water
The method used for the preparation of is -
1. Cold H2SO4 + BaO2.8H2O
2. HCl + BaO2
3. Conc. H2SO4 + Na2O2
4. H2 + O2
The oxide that gives hydrogen peroxide on the treatment with a dilute acid is –
(A)
(B)
(C)
(D)
The oxidising property of is best explained by assuming that two oxygen atoms in its molecule are.
(1) Bonded differently
(2) Bonded similarly
(3) Bonded covalently
(4) Bonded by hydrogen bonds