For the reaction 3A(g) + 2B(g) → 2C(g) + 2D(g) the following data were collected at constant temperature. Determine the correct rate law for this reaction. Trial Initial [A] Initial [B] Initial Rate (mol/L) (mol/L) (mol/(L·min)) 1 0.200 0.100 6.00 × 10–2 2 0.100 0.100 1.50 × 10–2 3 0.200 0.200 1.20 × 10–1 4 0.300 0.200 2.70 × 10–1

Answer :  The correct rate law becomes:

Explanation :

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

Rate law expression for the reaction:

where,

a = order with respect to A

b = order with respect to B

Expression for rate law for first observation:

....(1)

Expression for rate law for second observation:

....(2)

Expression for rate law for third observation:

....(3)

Expression for rate law for fourth observation:

....(4)

Dividing 1 by 2, we get:

Dividing 3 by 1, we get:

Thus, the rate law becomes:

3

explanation:

1.solid

2.carbon dioxide

3.helium