In the manufacture of $H_2SO_4$ by the contact process,$As_2O_3$ acts as a .......

How does a solid catalyst enhance the rate of combination of gaseous molecules?

The variation of the rate of an enzyme-catalyzed reaction with substrate concentration is correctly represented by which graph?

Two percent of ethanol is added during the oxidation of chloroform to stop the formation of carbonyl chloride. In this reaction,ethanol acts as:

$A$ catalyst is a substance that . . . .

Which reaction characteristics are changing by the addition of a catalyst to a reaction at constant temperature: $(i)$ Activation energy,$(ii)$ Equilibrium constant,$(iii)$ Reaction entropy,$(iv)$ Reaction enthalpy?