Zadania z chemii IB HL

(a) Outline two features of this experiment that ensure that the propanal intermediate is not a major product.

(b) Outline two safety precautions that must be taken during the preparation of propanoic acid, besides wearing a lab coat and safety goggles.

(d) The student used distillation to obtain pure propanoic acid from the reaction mixture. (i) State two impurities, apart from unreacted propan-1-ol, that were present in the propanoic acid before distillation. (ii) The approximate experimental yield of…

(e) The propanoic acid obtained by the distillation was an aqueous solution with a volume of 22.5 $\mathrm{cm^3}$. Three 5.00 $\mathrm{cm^3}$ samples of this solution were titrated with 0.200 $\mathrm{mol\,dm^{-3}}$ $\ce{NaOH}$ to determine the accurate…

Determine the mass of sodium thiosulfate pentahydrate, $\ce{Na2S2O3 * 5H2O}$, needed to prepare 250.0 $\mathrm{cm^3}$ of a 0.2000 $\mathrm{mol\,dm^{-3}}$ solution.

Explain how the 0.2000 $\mathrm{mol\,dm^{-3}}$ solution is prepared in a volumetric flask from the weighed solid.

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.

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

Before use, the EDTA solution was standardized against a standard solution of $\ce{Cu^2+}$ ions. An accurately weighed piece of pure copper wire was dissolved in the minimum volume of concentrated nitric acid and the mixture was warmed gently until no more…