If you add hydrochloric acid to marble chips carbon dioxide gas is made. By counting the number of bubbles of gas produced each minute you can tell how fast the reaction is happening. Below are the results of an investigation to see how changing the temperature of hydrochloric acid changes the rate of reaction. Marble chips of the same size were added to the same amount of the same strength acid. (°C) 1. What was the independent variable? What was the dependent variable? Suggest two control variables. 3. Add the averages into the table. 4. Plot a line graph. Average number of bubbles produced per minute goes up the side. Temperature of acid goes along the bottom. 5. What happens to the rate of reaction as the temperature goes up? Explain why. Use the words particles, energy and collisions. 7. Which cross would you say was wrong (anomalous)?