Which of the following disaccharide will not reduce Tollen's reagent?

Write the balanced chemical equation for developing a back and white photographic film. Also explain why the solution of sodium thiosulphate on acidification turns milky white.

$$F{e^{3 + }}\buildrel {SN{C^ - }(excess)} \over \longrightarrow $$ blood red $$F{e^{3 + }}\buildrel {SN{C^ - }(excess)} \over \longrightarrow $$ colourless (B):

(A) Identify compound A and B and write their IUPAC names.

(B) Determine the spin only magnetic moment of B.

For the following reaction

2X(g) $$\to$$ 3Y(g) + 2Z(g)

assuming ideal gas conditions, the data for change of partial pressure with time is as follows:

$$ \begin{array}{llll} \hline \text { Time (in min) } & 0 & 100 & 200 \\ \hline \begin{array}{l} \text { Partial pressure of X } \\ \text { (in mm of Hg) } \end{array} & 800 & 400 & 200 \end{array} $$

Calculate

(A) Order of reaction.

(B) Rate constant.

(C) Time taken for 75% completion of reaction.

(D) Total pressure of the reaction mixture when $$p_x=700$$ mm.