The rates of chemical reactions can be influenced by several factors such as the concentration of reactants, temperature, surface area of reactants, catalysts, and the presence of mixing or agitation. In this particular scenario, we are dealing with the concentration of hydrochloric acid (HCl) as a key factor affecting the reaction rate.
From the given experimental record, we can observe the following data points:
- Flask 1: 25 mL of HCl, 0 mL of Water, Time = 11.2 seconds
- Flask 2: 20 mL of HCl, 5 mL of Water, Time = Unknown
- Flask 3: 15 mL of HCl, 10 mL of Water, Time = Unknown
- Flask 4: 10 mL of HCl, 15 mL of Water, Time = Unknown
As the volume of HCl decreases from Flask 1 to Flask 4, the concentration of HCl in the solution also decreases. Since HCl is a reactant in the chemical reaction with calcium carbonate, a lower concentration of HCl means there are fewer HCl molecules available to collide with calcium carbonate particles. As a result:
- The reaction rate will decrease.
- The time taken for the reaction to complete will increase.
Therefore, the expected trend in the table is that the time taken for the reaction increases as the volume of hydrochloric acid decreases.
The correct answer is:
Time increases as the volume of hydrochloric acid decreases.
