Chem Practical Planning Questions with Anskey

Pei Hwa Secondary School Secondary 4 Pure Chemistry 6092 Practical: Planning Question Practices Name: ………………………………… ( ) Class / TG : …………… Date: ……………….… 1 1 X is zinc powder contaminated with carbon. Plan an experiment to purify X and determine the percentage purity of X. You can assume all the apparatus and reagents normally found in a school laboratory are available. In your method you should note any other assumptions that you make, include the measurements you would take and explain how you would use your results determine the percentage purity of X. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………[5]

2 2 Eggshells and cockleshells are some common substances that contain calcium carbonate. However, the percentage by mass of calcium carbonate in each of these substances varies. (a) Outline a method you could use to determine whether an eggshell or a cockleshell contains a higher percentage by mass of calcium carbonate. You can assume all the apparatus and reagents normally found in a school laboratory are available. You should include in your answer the measurements you would take, and explain how your results would show which type of shell contain a higher percentage by mass of calcium carbonate. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………[5] (b) State an assumption that is made in the experimental method outlined in 2(a). …………………………………………………………………………………………………… …………………………………………………………………………………………………[1]

3 3 Metal carbonates undergo thermal decomposition to produce metal oxides and carbon dioxide. The more reactive a metal is, the more difficult it is to decompose its carbonate. You are required to plan an experiment to determine the order of the reactivity of the metals calcium, copp