Question

Fill in the blanks by choosing the correct option;
Order of the reaction is the __$X$__ of the powers to which concentration terms are raised in experimentally determined rate equation. The unit of first order rate constant is __$Y$__. The unit of first order rate constant when concentration is measured in terms of pressure and time in minutes is __$Z$__.

• A. $X\to product,Y\to mol{L}^{-1}tim{e}^{-1},Z\to atmmi{n}^{-1}$
• B. $X\to sum,Y\to Lmo{l}^{-1}tim{e}^{-1},Z\to atmmi{n}^{-1}$
• C. $X\to product,Y\to Lmo{l}^{-1},Z\to atmmi{n}^{-1}$
• D. $X\to sum,Y\to tim{e}^{-1},Z\to mi{n}^{-1}$

Answer 1

The correct option is D $X\to sum,Y\to tim{e}^{-1},Z\to mi{n}^{-1}$

The order of a chemical reaction is defined as the sum of the powers of the concentration of the reactants in the rate equation of that particular chemical reaction.

General formula for the unit of rate constant = mole${}^{(1-n)}$ L${}^{(n-1)}$ min${}^{-1}$.

For 1${}^{st}$ order reaction,

n = 1

Therefore, unit of rate constant $=$ min${}^{-1}$

The unit of rate constant in terms of pressure and time:

mol ${}^{(1-n)}$ L ${}^{(n-1)}$ min${}^{-1}$ or atm${}^{(1-n)}$ min ${}^{-1}$

For 1${}^{st}$ order reaction,

n = 1

Therefore, the unit is min${}^{-1}.$

Hence, the correct answer is option $\text{D}$.