Q16.6P - Chemistry: Molecular Nature Of Matter And Change

Question

Ina kinetics experiment, a chemist places crystals of iodine in a closed reaction vessel, introduces a given quantity of hydrogen gas, and obtains data to calculate the rate of hydrogen iodide formation. In a second experiment, she uses the same amounts of iodine and hydrogen, but first warms the flask to 130 degrees Celsius, a temperature above the sublimation point of iodine. In which of these experiments does the reaction proceed at a higher rate? Explain.

Step-by-Step Solution

Answer

The answer is,

Reaction rate increases in the second experiment.

Step 1: Effect of temperature on reaction rate

The temperature is an important parameter which can be used to increase the rate of a reaction. The increase in temperature increases the energy of interaction and hence increases the number of collisions. The higher the collision energy and the higher the collision number, the reaction speed also increases.

Step 2: Explanation

The rate of the reaction increases in the second experiment. This is why because the increase in temperature of the reaction, increases the reaction rate. Heating the iodide above the sublimation temperature, causes the iodide to change into its gaseous state. The gaseous molecules on increase in temperature interacts more by the increase in collisions. Hence the reaction rate increases.