A – Wrong
Bromine water is the test for the presence of alkenes.
B – Correct
A burning splint makes a popping sound in hydrogen, goes out in carbon dioxide and then the glowing splint relights in oxygen.
C – Wrong
Limewater turns milky in the presence of carbon dioxide. However, no observations are made in the presence of hydrogen and oxygen.
D – Wrong
This is the test for acids. Blue litmus turns red in acid.
E – Wrong
This is the test for alkali. Red litmus turns blue in alkali.