Zadania z chemii IB SL

The iron(II) concentration is found by titrating against a standard solution of potassium manganate(VII), $\ce{KMnO4}$. At intervals of a few days, a 20.00 $\mathrm{cm^3}$ sample is withdrawn from each flask and made up to 250.0 $\mathrm{cm^3}$ with water;…

The student's results are shown in the graph. (i) Calculate the average rate at which the iron(II) concentration fell in the 24 h flask during the 21 days. Include units. (ii) Before starting, the student proposed the hypothesis: "The longer a solution is left…

Suggest one way of extending the investigation so that further recommendations about storing the iron(II) solution could be made.

The enthalpy of combustion of $\ce{C19H40}$ is $-12\,660\ \mathrm{kJ\,mol^{-1}}$. (i) Calculate the maximum energy released when 1.50 g of $\ce{C19H40}$ is burned completely. (ii) Determine the maximum temperature increase when $400.0\ \mathrm{cm^3}$ of water…