1. The problem involves analyzing the relationship between the concentration of salt solution (in mol dm⁻³) and the mean change in mass of potato pieces (in grams). 2. From the description, the graph starts at $y=0.2$ when $x=0$, decreases steadily, crosses the x-axis near $x=0.25$, and continues downward to about $y=-0.3$ at $x=1.0$. 3. This suggests a negative correlation between salt concentration and mass change: as salt concentration increases, the potato pieces lose mass. 4. The point where the curve crosses the x-axis ($y=0$) near $x=0.25$ indicates the concentration at which there is no net change in mass. 5. The curve shape implies a nonlinear relationship, possibly quadratic or exponential decay, but exact function fitting requires data points. 6. In summary, increasing salt concentration causes the potato pieces to lose mass, with no change at approximately $0.25$ mol dm⁻³ salt concentration.