"Sodium alginate solution" vs. "Alginic acid"

[Nahahahah]

Hi everyone.
I'm doing research with sodium alginate (NaC6H7O6) and I really need your help.

Sodium alginate is a cell wall component of seaweed or brown algae.
During the research, I read some pages telling that we can get alginic acid by dissolve sodium alginate in water.

But what I think is that, if the NaC6H7O6 is dissolve in water, it will ionized and loss Na+.
Then the solution will be a base, not an acid...
And I test the pH with sodium alginate solution and I got a pH 7
(Actually, I didn't dissolve much powder)

Is it right that the solution of sodium alginate is a really acid?

 

[Borek]

How did you test for pH?

NaC₆H₇O₆ is an experimental formula, not the real one (not that it matters much, just for clarification), as the alginic acid is a natural polymer.

Solution of alginate should have pH a bit on the basic side, typical for solutions of salts of weak acids. No idea what water you have used for dissolving and what is the concentration, so it is a bit difficult to comment on, but in general DI water is typically a bit acidic due to the dissolved CO₂, if the pH of the solution is 7 chances are it is already more alkaline than it was before.