A student, took four metals P, Q, R and S and carried out different experiments to study the properties of metals. Some of the observations were :

• All metals could not be cut with a knife except metal R.
• Metal P combined with oxygen to form an oxide M₂O₃ which reacted with both acids and bases.
• Reaction with water.
  
  • P – Did not react either with cold or hot water but reacted with steam
  • Q – Reacted with hot water and the metal started floating
  • R – Reacted violently with cold water.
  • S – Did not react with water at all

Based on the above observations answer the following:

Metal which forms amphoteric oxides is

1. P
2. Q
3. R
4. S

A student, took four metals P, Q, R and S and carried out different experiments to study the properties of metals. Some of the observations were :

• All metals could not be cut with a knife except metal R.
• Metal P combined with oxygen to form an oxide M₂O₃ which reacted with both acids and bases.
• Reaction with water.
  
  • P – Did not react either with cold or hot water but reacted with steam
  • Q – Reacted with hot water and the metal started floating
  • R – Reacted violently with cold water.
  • S – Did not react with water at all

Based on the above observations answer the following:

The increasing order of the reactivity of the four metals is;

1. P < Q < R < S
2. S < R < Q < P
3. S < P < Q < R
4. P < R < Q < S

The figure shown below represents a common type of dialysis called as Haemodialysis. It removes waste products from the blood such as excess salts, and urea which are insufficiently removed by the kidney in patients with kidney failure. During the procedure, the patient's blood is cleaned by filtration through a series of semi-permeable membrane before being returned to the blood of the patient. On the basis of this, answer the following questions:

The haemodialyzer has semi-permeable lining of tubes which help to:

1. To maintain osmotic pressure of blood.
2. To filter nitrogenous wastes from the dialyzing solution.
3. In passing the waste products in the dialyzing solution.
4. To pump purified blood back into the body of the patient.

A student, took four metals P, Q, R and S and carried out different experiments to study the properties of metals. Some of the observations were :

• All metals could not be cut with a knife except metal R.
• Metal P combined with oxygen to form an oxide M₂O₃ which reacted with both acids and bases.
• Reaction with water.
  
  • P – Did not react either with cold or hot water but reacted with steam
  • Q – Reacted with hot water and the metal started floating
  • R – Reacted violently with cold water.
  • S – Did not react with water at all

Based on the above observations answer the following:

Out of the given metals, the metal Q is

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