In which of the following reactions will cyanide be obtained as a major product?

Which one of the following oxides is reduced by water gas to obtain the metal during its extraction?

The distance between the foci of the hyperbola $x^2 - 3y^2 - 4x - 6y - 11 = 0$ is

The electrochemical equivalent of a metal is $x \ g \ C^{-1}$. The equivalent weight of the metal is:

$AgNO_3 \xrightarrow{\Delta} (W) + (X) + O_2$
$(X) + H_2O \to HNO_2 + HNO_3$
$(W) + HNO_3 \to (Y) + NO + H_2O$
$(Y) + Na_2S_2O_3 (\text{excess}) \to (Z) + NaNO_3$
Identify $(W)$ to $(Z)$.

On a new scale of temperature (which is linear) called the $W$ scale,the freezing and boiling points of water are $39\,^{\circ}W$ and $239\,^{\circ}W$ respectively. What will be the temperature on the new scale,corresponding to a temperature of $39\,^{\circ}C$ on the Celsius scale? ............ $^{\circ}W$