What gases can a flying balloon be filled with?

To­day we’ll dis­cuss two cu­ri­ous prop­er­ties of hy­dro­gen. Can you guess what they are?

Safe­ty pre­cau­tions

At­ten­tion! All ex­per­i­ments are per­formed by pro­fes­sion­als. Do not at­tempt.


  • flask with tar­tar­ic acid so­lu­tion;
  • mag­ne­sium strips;
  • bal­loon;
  • thread with screw-nut;
  • fire­place match­es.

Process de­scrip­tion

Mag­ne­sium and tar­tar­ic acid re­act to re­lease hy­dro­gen gas:

C₄H₆O₆ + Mg → MgC₄H₄O₆ + H₂↑

Hy­dro­gen gas is 15 times lighter than air, and there­fore a bal­loon filled with it can float. It ex­plodes if ex­posed to flame due to the vi­o­lent re­ac­tion be­tween hy­dro­gen and oxy­gen, which forms wa­ter:

2H₂ + O₂ → 2H₂O

The en­er­gy re­leased in this re­ac­tion can safe­ly be uti­lized to pow­er so-called hy­dro­gen ve­hi­cles.

Amus­ing and safe ex­per­i­ments await you in the MEL Chem­istry sub­scrip­tion!