Zadania z chemii IB HL

The colorimeter can record either absorbance or percentage transmittance at a chosen wavelength. Outline why one particular wavelength has to be selected.

Deduce the equation that relates absorbance to concentration for these solutions, including the numerical value of the constant.

Estimate the absorbance of a 0.400 $\mathrm{mol\,dm^{-3}}$ solution of nickel(II) sulfate.

Predict the difference, if any, between the absorbance of the 0.400 $\mathrm{mol\,dm^{-3}}$ solution read from the extrapolated line and the value calculated from the equation in 3d.

Nickel(II) sulfate solution is green. Deduce the most suitable wavelength for this colorimetry, using section 15 of the data booklet.

State, in terms of equilibrium concentrations, the expression for $K$, the equilibrium constant of this reaction.

By the time equilibrium was reached, the vessel held 1.7 mol of $\ce{H2(g)}$. Calculate the equilibrium amounts, in mol, of the three remaining gases, then use them to calculate $K$.

In a molten carbonate fuel cell the mixture of hydrogen and carbon dioxide from the reaction is fed to the anode, while a mixture of oxygen and carbon dioxide is fed to the cathode. Carbonate ions, $\ce{CO3^2-}$, move through the molten electrolyte from the…