Zadania z chemii IB HL

Suggest how to prepare 100.0 $\mathrm{cm^3}$ of a 0.05000 $\mathrm{mol\,dm^{-3}}$ sodium thiosulfate solution from the 0.2000 $\mathrm{mol\,dm^{-3}}$ solution.

The student's results are shown below. Each time was measured to ± 0.1 s. Concentration of $\ce{Na2S2O3}$ / $\mathrm{mol\,dm^{-3}}$ Time, trial 1 / s Time, trial 2 / s Time, trial 3 / s Time, trial 4 / s Time, trial 5 / s Average time / s 0.2000 ± 0.08 % 17.2…

The average times were plotted against concentration. Draw a curve of best fit through the points on the graph.

A second student repeated the experiment with the same five solutions and the same apparatus and obtained the following times. Concentration of $\ce{Na2S2O3}$ / $\mathrm{mol\,dm^{-3}}$ Reaction time / s (± 0.1 s) 0.2000 ± 0.08 % 20.1 0.1000 ± 0.2 % 37.5 0.0500…

State one safety concern arising from a product of this reaction, and a precaution that should be taken because of it.

Tin and iodine are elements, whereas tin(IV) iodide is a compound. Describe, with reference to these three substances, how an element differs from a compound.

Outline why solid tin(IV) iodide is classified as a polar covalent compound. Use sections 9 and 17 of the data booklet.

Contrast tin and tin(IV) iodide in terms of one physical property.

Calculate the wavelength, in m, of the limit of convergence in the line emission spectrum of tin. Use sections 1, 2 and 9 of the data booklet.