By what factor does the rate change in each of the following cases (assuming constant temperature)?
Factor (enter as decimal if <1)
(a) A reaction is first order in reactant A, and [A] is doubled.
(b) A reaction is second order in reactant B, and [B] is halved.
(c) A reaction is second order in reactant C, and [C] is tripled.

a) The rate of reaction increases by factor of 2.

b) The rate of reaction increases by factor of 0.25.

c) The rate of reaction increases by factor of 9.

Explanation:

a)

Rate of the reaction ;

if [A] is doubled, then rate of the reaction = R'

The rate of reaction increases by factor of 2.

b)

Rate of the reaction ;

if [B] is halved, then rate of the reaction = R'

The rate of reaction increases by factor of 0.25.

c)

Rate of the reaction ;

if [C] is tripled, then rate of the reaction = R'

The rate of reaction increases by factor of 9.

they are made of gases.

they have a spherical shape.

they make energy through fusion.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.