2007-08-06 18:10:39 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Because hydrogen is ligher than air, so it tends to rise. It would move to the top of the tube, and then not be able to escape.
2007-08-06 18:15:38 · answer #1 · answered by kt 7 · 0⤊ 0⤋
Because Hydrogen is lighter than air. If the opening is up the Hydrogen will float away. If the opening is down the hydrogen will float up to the top of the tube.
2007-08-06 18:13:40 · answer #2 · answered by greeny960 2 · 2⤊ 0⤋
Density of hydrogen gas is 0.08988 g/L
The density of air at sea level is about 1.2 kg/m3(1.2 g/L).
Hydrogen gas is very, very light weight as compared with air. So to collect hydrogen gas test tubes are kept with their mouth downward.
2007-08-06 20:01:03 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Hydrogen gas is lighter than air, and so would escape the tube if help with the opening upwards.
2007-08-06 18:14:45 · answer #4 · answered by vivere_est_cogitare 1 · 0⤊ 0⤋
to keep the hydrogen from escaping the test tube
2007-08-06 18:59:25 · answer #5 · answered by Anonymous · 0⤊ 0⤋