When you immerse an egg in vinegar the shell will slowly disappear, leaving a flexible and bouncy egg. Bread dough leavens when you use baking soda.
Find out in this episode the reasons for these phenomena.

References

Inorganic Chemistry by C. E. Housecroft, A. G. Sharpe 1st Ed. 2001 ISBN 0582-31080-6
General Chemistry by D. D. Ebbing 5th Ed. 1996 ISBN 0-395-74415-6
Organic Chemistry by Clayden, Warren & Wothers
https://en.wikipedia.org/wiki/Sodium_bicarbonate
https://en.wikipedia.org/wiki/Proton
The eggshell in vinegar experiment: https://www.youtube.com/watch?v=khgOTDvG-4A
https://en.wikipedia.org/wiki/Baking_powder