For the reactions $C + O2 \rightarrow CO2$; $\, \Delta H = -393 \, \text{kJ} 2Zn + O2 \rightarrow 2ZnO$, $\, \Delta H = -412 \, \text{kJ}$ $\text{the correct statement is:}$

100 g of O2 and 100 g of He(g) are in separate containers of equal volume. Both gases are at 100°C. Which one of the following statements is true?

A cell has been set up as shown in the following diagram and E$^0$ has been measured as 1.00V at 25°C. Calculate $\Delta$G$^0$ for the reaction.

Which of the following is used as a food preservative?

Which of the following flux is used to remove acidic impurities in metallurgical processes?

The emf of a particular voltaic cell with the cell reaction $Hg_{2}^{2+}+H_{2} {\rightleftharpoons} 2Hg+2H^{+}$ is 0.65 V. The maximum electrical work of this cell when 0.5 g of $H_{2}$ is consumed.

What is X?

A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives

Which one of the following statements is not true regarding (+) Lactose ?

Which group contains coloured ions out of 1. $Cu^{2+}$ 2.$Ti^{4+}$ 3. $Co^{2+}$ 4. $Fe^{2+}$

The standard reduction potential for $Cu^{2+} / Cu$ is + 0.34. Calculate the reduction potential at pH = 14 for the above couple is:
$K_{sp}\space of \space Cu(OH)_2\space is \space 1.0\times10^{-19}$.

For a first order reaction $A \to P,$ the temperature (T) dependent rate constant (k) was found to followthe equation log k=- (2000) $\frac{1}{T}+6.0.$ The pre-exponential factor A and the activation energy $E_{a,}$ respectively, are

A certain reaction is non spontaneous at 298K. The entropy change during the reaction is 121 $JK^{-1}.$ Is the reaction is endothermic or exothermic ? The minimum value of $\Delta$H for the reaction is