If NaOH is added to an aqueous solution of Zn2+ ions, a white precipitate appears and on adding axcess NaOH, the precepitate dissolves. In this solution zinc exists in the:
1. cationic part
2. anionic part
3. both in cationic and anionic parts
4. there is no zinc left in the solution
Brine is chemically:
1. conc. solution of Na2CO3
2. conc. solution of Na2SO4
3. conc. solution of NaCl
4. conc. solution of alum
NO2 is obtained by heating:
Soda lime is:
1. Na2CO3 + CaO
2. NaOH + NaHCO3
3. NaOH + CaO
4. NaH + Na2CO3
Molecular formula of Glauber's salt is :
Among the following, which has minimum solubility in water?
Common table salt becomes moist and does not pour easily in rainy season because:
1. It contains magnesium chloride.
2. It contains magnesium carbonate.
3. It melts slightly in rainy season.
4. Sodium chloride is hygroscopic.
A mixture of Al(OH)3 and Fe(OH)3 can be separated easily by treating it with:
Alkali metals are characterised by:
1. Good conductors of heat and electricity.
2. High melting points.
3. Low oxidation potentials.
4. High ionisation potentials.
Excess of dilute sodium hydroxide solution is gradually added with shaking to an aqueous solution of zinc sulphate. What would you observe?
1. A light blue precipitate is first formed which finally dissolves to give a deep blue solution
2. A white precipitate appears which dissolves to give a colourless solution.
3. A white precipitation is formed which does not dissolve
4. No change takes place and the solution remains clear