Identify name of from following.

Which of the following compounds is used to convert acetaldehyde into acetaldehyde cynanohydrin?

What volume of chlorine gas (molar mass 71) is evolved at STP during electrolysis of fused NaCl by passage of 1 amp current for 965 second? (At STP, V $=22.4 \mathrm{~dm}^3$ )

Identify the test from following so that aldehyde when boiled with ammoniacal silver nitrate solution deposts silver.