Which sample of HCl reacts at the fastest rate with a 1.0 - gram sample of iron filling

Question:

The options are;

a. 10. mL of 1 M HCl (aq) at 10. oC

b. 10. mL of 1 M HCl (aq) at 25oC

c. 10. mL of 3 M HCl (aq) at 10. oC

d. 10. mL of 3 M HCl (aq) at 25oC

Answer:

The correct option is;

d. 10 mL of 3 M HCl (aq) at 25 °C

Explanation:

Factors that influence the rate of the reaction include;

Concentration and

Temperature

Concentration

An increase in concentration leads to a increased number of interaction among the the reacting components of HCl and iron filings such that the number of effective interaction or the rate of the reaction increases, therefore, a 10 mL 3 M HCl will react faster than a 10 mL of 1 M HCl.

Temperature

When the temperature of the reacting HCl is increased, the energy within the reacting system increases leading to an increase in the number of high energy collisions which results in an increased reaction rate, therefore, HCl at 25 °C will react faster than HCl at 10 °C.

Hence the correct option is 10 mL of 3 M HCl (aq) at 25 °C.