Which of the following are correct?
i. Basic structural unit of silicates is –\( \text{-RSiO-} \)
ii. Silicones are biocompatible
iii. Producer gas contains CO and \( \text{N}_2 \)

1 gram of sodium hydroxide was treated with 25 ml. of 0.75 M HCI solution, the mass of sodium hydroxide left unreacted is equal to :
Identify Z in the following reaction sequence.

In the given circuit, if the potential at point B is 24 V, the potential at point A is:
