how do i do the lime test for finding hydrogen?

Answer 1

Lime water is used to test for carbon dioxide. Lime water is a clear solution of Ca(OH)2, which is slightly soluble in water. If you bubble the unknown gas through the solution, a precipitate appears, the solution becomes cloudy white.

Ca(OH)2(aq) + CO2(g) ===> CaCO3(s) + H2)

People usually demonstrate presence of hydrogen by collecting the gas in a test tube, holding the test tube upside-down (so the lighter-then-air H2 gas doesn't rise and escape), and put a glowing splinter to the mouth of the test tube. The result is a loud whistling pop/

Answer 2

You don't. I take it you're on your way to doing key stage 3 and doing the three tests for finding the presence of oxygen, carbon dioxide and hydrogen.

Carbon dioxide uses the bubble the gas through lime water test. You have the carbon dioxide producing substances combined in a test tube, you attach a delivery tube to the top, and you put the other end of the delivery tube in a container filled with clear lime water. If there is carbon dioxide present, the lime water will turn cloudy as it bubbles through the liquid.

The presence of hydrogen test is that you collect the gas in an upturned test tube, you put a lighted splint at the base and you listen for the popping sound. It's a crude test.

The oxygen test is similar, but you blow out the splint so that it's still glowing red when you put it inside the gas filled upturned test tube and you watch as it relights itself.

Answer 3

lime test is done to identify dissolve carbon dioxide.