Calcium hydride can be obtained by heating :
1. Calcium oxide with hydrogen.
2. Calcium oxide with hydrogen under pressure.
3. Calcium with hydrogen under pressure.
4. Calcium with hydrogen at a very low temperature.
Mark the incorrect statement:
(1) Alkali metals are strong reducing agents.
(2) The electropositive nature of alkali metals decreases with increase in atomic number.
(3) Alkali metals have relatively low electronegativity values.
(4) On burning in oxygen lithium forms only the monoxide while other alkali metals form peroxides and or superoxides.
A hydrated water soluble salt, A in solution gives a turbidity with dilute hydrochloric acid evolving a gas with a suffocation odour. The solution of A decolourises lodine solution. A is likely to be
1. KI
2.
3.
4.
Which of the following compounds may be soluble in pyridine-
(1) Barium chloride
(2) Sodium chloride
(3) Lithium chloride
(4) Potassium chloride
Which of the following is a false statement-
(1) Sodium oxide is more basic then magnesium oxide.
(2) Beryllium oxide is amphoteric
(3) The thermal stability of beryllium carbonate is more than that of calcium carbonate
(4) Beryllium is amphoteric
The basic character of oxides MgO, SrO, , NiO and increases in the order –
(1)
(2)
(3)
(4)
Which of the following ions is the best conductor of electricity in aqueous solution –
(1)
(2)
(3)
(4)
Among the following, the incorrect statement is–
1. Lithium is the softest among all the alkali metals
2. Lithium possesses higher melting and boiling points
3. It is least reactive among alkali metals
4. It forms chloride which is soluble in alcohol
The correct order of increasing lattice energy of the metallic compounds is –
(1) NaCl < CaO < NaI < BaO
(2) NaI < NaCl < BaO < CaO
(3) NaCl < NaI < BaO < CaO
(4) NaI < NaCl < CaO < BaO
Which alkali metal has the lowest melting point and exists as a liquid at 30 degree temp–
(1) Na
(2) K
(3) Rb
(4) Cs