# Help me !

1. Jun 25, 2004

### anastasia

help me!!!!!!!!!!!

somebody who can help me to answer this question.thanks a lot.

CALCULATE THE CONCERNTRATION OF THE RESULTING SOLUTION WHEN 300cm3 OF 0.4 mole/ dm3 Na2SO4 IS MIXED WITH 200cm3 OF 1.2 mole/dm3 OF Na2SO4.WHAT ARE THE MOLAR CONCERNTRATION OF SODIUM AND SULPHATE IONS IN THE RESULTING SOLUTIONS.

please send me an email at cutepie_fungurlz@yahoo.com before tomorrow in the evening. thanks a lot i really need somebody to help me...

2. Jun 25, 2004

### Gokul43201

Staff Emeritus
Hi Anastasia, welcome to PF !

Find the number of moles in each batch of solution (product of concentration and volume). The total number of moles divided by the total volume is the final concentration of Na2SO4.

Now you also want the concentrations of the Na+ and (SO4)2- ions. Write down the equation for the dissociation of Na2SO4 into its ions and balance it. This tells you how many moles of Na+ and (SO4)2- are made from each mole of Na2SO4. Use these ratios to find the number of moles of these ions.