Zadania z chemii IB HL

The three percentages in 2b add up to more than 100 %. Suggest an error that would explain this result and how it could be reduced or eliminated.

The results did not support the student's hypothesis. Suggest what the student overlooked when forming the hypothesis.

In a separate experiment, the students needed to separate a mixture of two miscible liquids, ethanol and pentan-1-ol. State the most suitable method of separation and the physical property on which it depends.

Deduce the electron configuration of the $\ce{Fe^3+}$ ion.

When potassium thiocyanate solution is added to a pale yellow solution containing iron(III) ions, the following equilibrium is established. $\ce{[Fe(H2O)6]^3+(aq) + SCN^-(aq) <=> [Fe(SCN)(H2O)5]^2+(aq) + H2O(l)}$ $\ce{[Fe(H2O)6]^3+(aq)}$ is pale yellow and…

Which property is the same for ammonia molecules containing deuterium, $\ce{ND3}$, and ordinary ammonia molecules, $\ce{NH3}$? A. Molar mass B. Molecular geometry C. Density of the gas at STP D. Rate of diffusion

(i) State the independent variable and the dependent variable of the investigation. (ii) Apart from the mass of leaves and the volume of water, suggest two other conditions that should be kept constant for the comparison between boiling times to be valid.…

(i) State what the graph shows about the relationship between the boiling time and the amount of oxalate ions extracted. (ii) Comment on the range of boiling times and on the number of measurements made in the investigation.