Introduction to the particulate nature of matter

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.

A beaker contains a clear, colourless solution of potassium nitrate in water. What is the type of mixture and the best method of obtaining the solid salt from it? A. heterogeneous, by filtration B. heterogeneous, by evaporation C. homogeneous, by filtration D.…

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.

The student recorded the following masses. Sample Mass / g (± 0.01 g) Percentage by mass Mixture before separation 6.35 not applicable Iron after separation 2.58 Calcium carbonate after separation 1.71 Potassium chloride after separation 2.31 36.4 % Calculate…

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.

The kinetic molecular theory describes matter as particles in constant motion. State and explain two physical properties of a gas using this model.

Which methods for separating the components of the given mixtures are correct? Mixture Method I. Two miscible liquids with boiling points of 56 °C and 118 °C Distillation II. The coloured pigments extracted from a leaf Paper chromatography III. A solid…