Gary Horner Solutions for Chapter: Evidence, Exercise 8: Experiment

List three observations when sodium and potassium metal are dropped into water. 

Sodium and potassium react vigorously with water and disappears when they are dropped in water. What flame colour did you observe from each reacting metal?

What did you notice about the level of reactivity of sodium compared to potassium when they are dropped in water?

Recall the reaction of the metals such as potassium and sodium with water. What does the colour of the universal indicator tell you about the initial and final $\mathrm{pH}$ of the water solution? Estimate the $\mathrm{pH}$ of the resulting solution.

Write the word equations to describe the reactions of sodium and potassium with water.

Write and balance the chemical equations for both the reactions of potassium and sodium with water.

Consider some typical metals and their physical and chemical characteristics. For example, a lead fishing sinker is denser than water and sinks to the bottom of the lake; an iron nail corrodes in air, but very slowly. Consider what happens if you drop a piece of copper, aluminium or iron into water. Describe how the behaviour of the alkali metals are different from other metals.