Hypothesis: If you can measure the pH of a range of acids and bases using a universal pH indicator, then you can use those values to calibrate a cabbage pH indicator.

Which method helped you prove this hypothesis? Check all that apply.

Using various concentrations of HCl and NaOH to measure a range of pH

Using an existing scale to determine pH

Knowing that the cabbage indicator always has the same color at a given pH value

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?