posted by eliz .
2.500g sample of a mixture of sodium carbonate and sodium chloride is dissolved in 25.00ml of 0.798M HCl. Some acid remains after the treatment of the sample. If 28.7 ml of 0.0108M NaOH were required to titrate the excess hydrochloric acid how many moles of sodium carbonate were present in the original sample?
How do i go about working this problem?
I know it has to do somthing with changing the Molarity into moles, but what do i do to get the original sample of moles present.