The colour of the precipitate formed on adding NaOH solution to iron (II) sulphate solution is:

1. White
2. Brown
3. Green
4. Pale blue

A metal which produces hydrogen on reacting with alkali as well as with acid:

1. Iron
2. Magnesium
3. Zinc
4. Copper

Which of the following is the best reagent to distinguish lead nitrate and zinc nitrate ?

P NaOH solution

Q KOH solution

R NH₄OH solution

1. Only P

2. Only R

3. Only Q

4. Both P and Q

A student takes Cu, Al, Fe and Zn strips, separately in four test tubes labeled as I, II, III and IV respectively. He adds 10 ml of freshly prepared ferrous sulphate solution to each test tube and observes the colour of the metal residue in each case.

He would observe a black residue in the test tubes:

1. (I) and (II)
2. (I) and (III)
3. (II) and (III)
4. (II) and (IV)