Applying Concepts These questions test conceptual learning. Four groups of students...

Applying Concepts

These questions test conceptual learning.

Four groups of students from an introductory chemistry laboratory are studying the reactions of solutions of alkali metal halides with aqueous silver nitrate, AgNO₃. They use these salts.

Group A: NaCl

Group B: KCl

Group C: NaBr

Group D: KBr

Each of the four groups dissolves 0.004 mol of their salt in some water. Each then adds various masses of silver nitrate, AgNO₃, to their solutions. After each group collects the precipitated silver halide, the mass of this product is plotted versus the mass of AgNO₃ added. The results are given on this graph.

(a) Write the balanced net ionic equation for the reaction observed by each group.

(b) Explain why the data for groups A and B lie on the same line, whereas those for groups C and D lie on a different line.

(c) Explain the shape of the plot observed by each group. Why do the plots level off at the same mass of added AgNO₃ (0.75 g) but give different masses of product?