Suppose you measure reactant concentration when increasing the volume of water used in each cup. A friend chose to measure reactant concentration by dropping more than one antacid tablet into equal quantities of water. Will your graph look the same as your friend graph? Explain your reasoning.

Answer 1

Your graph will likely not look the same as your friend's graph. Here’s why:

1. Dilution Effects: When you increase the volume of water while keeping the amount of reactant (antacid tablet) constant, you are effectively diluting the concentration of the reactant in the solution. As the volume of water goes up, the concentration of the dissolved reactant in the water (measured as molarity or similar units) will decrease, leading to a downward trend in your graph.

2. Increased Reactant Amount: On the other hand, your friend is adding more than one antacid tablet into the same quantity of water. Each tablet contributes additional reactant to the solution, which means that even if the volume of water remains equal, the total amount of reactant is increasing with each additional tablet. This will cause the concentration of reactants in your friend's graph to increase as more tablets are added.

3. Concentration vs. Total Volume: In your case, as you increase only the volume of water (without increasing the number of reactant tablets), you are capturing a response that shows dilution. Your friend's graph captures a response that reflects an increase in concentration due to adding more reactants into a constant volume of water.

Therefore, while both graphs may show a relationship between volume and concentration, the nature of that relationship will be fundamentally different based on whether reactants are being diluted (your experiment) or concentrated (your friend's experiment).