Zadania z chemii IB SL

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The amount of $\ce{NO2}$

prepared was checked by titration. The gas was first absorbed in water:

\ce{2NO2(g) + H2O(l) -> HNO3(aq) + HNO2(aq)}

The resulting solution was made up to 200.0

\mathrm{cm^3}

in a volumetric flask, and 20.0

\mathrm{cm^3}

portions…

Suggest a sequence of experimental steps that would give a pure sample of each of the three components.

Describe how a standard aqueous solution of potassium manganate(VII) can be prepared from the solid.

Describe the steps by which this standard solution is turned into a calibration curve for the colorimeter.

In moist air carbonyl dibromide is slowly hydrolyzed: $\ce{Br2CO(g) + H2O(g) -> CO2(g) + 2HBr(g)}$ (i) Suggest a method of monitoring the progress of this reaction at constant temperature so that its rate can be determined. (ii) Outline two reasons why a…

Which of the following could be used to follow the progress of the reaction between calcium carbonate and dilute nitric acid? $\ce{CaCO3(s) + 2HNO3(aq) -> Ca(NO3)2(aq) + H2O(l) + CO2(g)}$ I. A balance recording the mass of the open flask and its contents II. A…

Describe how the student should prepare this standard solution from the weighed solid using a 250.0 $\mathrm{cm^3}$ volumetric flask.

The student pipetted 25.00 $\mathrm{cm^3}$ of the potassium hydroxide solution into a conical flask and titrated it with nitric acid, $\ce{HNO3(aq)}$ , of concentration 0.1250 $\mathrm{mol\,dm^{-3}}$ . The burette readings before and after the titration are…

Explain why the potassium hydroxide solution has to be standardized before it is used in the titration. Assume that there are no systematic errors in the procedure.

(i) Suggest one hazard to health or safety in Student A's procedure. (ii) Student A plotted the highest temperature of each mixture against the volume of nitric acid. With a ruler, draw two straight lines of best fit: one following the rising set of points and…