A student is investigating the rate of a neutralization reaction between 0.10 M HCl(aq) and 0.10 M NaOH(aq) carried out in a beaker at room temperature. The only instruments available for real-time monitoring are a pH meter and a conductivity probe. To obtain concentration–time data suitable for constructing a rate law, which instrument and corresponding measured quantity should the student select?
a) Conductivity probe; record total ionic conductivity and assume it is proportional to [H+]
b) pH meter; monitor the temperature change displayed on the meter as an indirect measure of reaction rate
c) pH meter; record pH values at regular intervals to calculate [H+]
d) Conductivity probe; use conductivity readings to compute pH at regular intervals