bio (1117) - Mab: [p] exhaled air pH

so.

one of the products of respiration is CO2, which we breathe out when we exhale. now they move around the body through the blood as well, and they are bumped around by hydrogen. so when we exhale, we're actually exhaling hydrogen too. therefore, our breath should be slightly acidic. we tested this today.

first of all, we got limewater, and blew into it using a straw. of course it turned milky, proving that we exhale CO2

the second part, the probe was being dodgy, so we skipped ahead to using universal indicator, which was also dodgy.

first it said our distilled water was acidic, so we had to change bottles.

so anyway.. it started off green (pH 7) and thompson blew into it for 2min. within the first 30 seconds though, it changed colour and came down to pinky-orange (pH 5) and that's where it stayed 'til the end pretty much