5 Responses

1. Sean Chua

   16|Apr|2008 1

   Hi. I am the founder & master trainer of SimpleChemConcepts.com.

   Your concept is correct. However, you are not answering to the question directly.
   Main question is asking you why the cake will only rise if “water” is added. Thus,
   the focus is on the word “water” itself.

   My suggested answer will be:
   In the cake mixture, there is sodium hydrogen carbonate and solid tartaric acid.
   However, the solid tartaric acid has no acidic properties and will not react with the
   carbonates. When water is added to the cake micture, the tartaric acid gains its
   acidic properties and react with the carbonates to form salt + water + carbon
   dioxide. The carbon dioxide produced will caused the rise of the cake.

   Hope this helps,
   Sean
   www.SimpleChemConcepts.com

2. JO.

   26|May|2008 2

   hi.
   i have an inquiry about this question regarding the acids and bases that i hope you can help me with.

   in the case that there is a weak acid (ethanoic acid) of higher concentration than the strong acid (sulphuric acid) of weaker concentration, and they are both made to react with calcium carbonate. which acid would be the one which produces more carbon dioxide?

   thank you.

3. Helen

   29|May|2008 3

   Hey … how r u ?

   I would like to ask you a question about a diagram of strong acids and weak acids which you had posted on the website … the diagram depics sulphurous acid as being a strong acid ……

   I used to think that sulphurous acid was known to be a weak acid and thus a weak electrolyte …

   so is it not that way ?

   by the way .. thanks alot for the great website.. you are doing a great job here

   thanks

4. sean

   07|Jun|2008 4

   Hi Jo,

   Comparing:

   A) Strong Acid (but with weak concentration)
   B) Weak Acid (but with high concentration)

   I will go for Answer A.

   Reason is because strong acid has 100% dissociation of H+ ions. Even when its
   concentration is low, there are enough H+ ions around.

   If you look at weak acid like ethanoic acid, no matter how migh you concentration
   is, the number of H+ ions is still very low. This is because for weak acid, there is
   only partial dissociation of acid to give small number of H+ ions.

   There is mention in most text books that for ethanoic acid, only 4% of H+ ions are
   dissociated. Most remain intact.

   Hope this is clear.

5. sean

   07|Jun|2008 5

   Hi Helen,

   I am doing fine. Will be conducting a 40hrs Intensive Chemistry Revision Bootcamp
   for Singapore students in a weeks time. Been very busy to make sure this Bootcamp
   will provide this special group of students with the tools & strategies for them to
   score that grade that they truly deserve.

   Back to your question, 1st i would want to differentiate:
   Sulphuric Acid H2SO4
   Sulphrous Acid H2SO3
   –> They are 2 different acids but have one similarity, they are STRONG ACID.

   WEAK ACID is usually fruit/organic acid such as acetic acid, ethanoic acid, etc.

   Hope you will find this information useful to u.