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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: xc630 on September 24, 2006, 05:50:04 PM

Title: sodium ion concentration
Post by: xc630 on September 24, 2006, 05:50:04 PM

Hi

70.0 mL of 3.0 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate. I need to find the sodium ion concentration. My question is what is formed when odium carbonate is added to sodium bicarbonate?

Title: Re: sodium ion concentration
Post by: Yggdrasil on September 24, 2006, 07:12:34 PM

Basically, you'll form a mixture of sodium carbonate and sodium bicarbonate  :P.  Any chemical reactions which happen will not affect the sodium ion concentration.

Title: Re: sodium ion concentration
Post by: xc630 on September 24, 2006, 07:54:04 PM

so then how would i find the concentration of the entire solution?

Title: Re: sodium ion concentration
Post by: Yggdrasil on September 24, 2006, 08:34:30 PM

1.  Find the amount (i.e. number of moles) of sodium ions in 70.0mL of 3.0M sodium carbonate.

2.  Find the amount of sodium ions in 30.0mL of 1.0M sodium bicarbonate.

Hint:  Sodium carbonate = Na₂CO₃ and sodium bicarbonate = NaHCO₃

3.  Find the total volume when you mix the two solutions.

4.  Add the results from (1) and (2) to find the total amount of sodium ions in your mixture.

5.  Divide the moles of sodium ions (from 4) by the total volume (from 3) to find the concentration of sodium ions in your mixture.