A25.00 ml aliquot of concentrated hydrochloric acid (11.7m) is added to 175.00 ml of 3.25m hydrochloric acid. determine the number of moles of hydrochloric acid from 175.00 ml of 3.25 m hydrochloric acid solution.

The number of moles of hydrochloric acid are 0.861

Explanation:

In first solution, the [HCl] is 11.7 M, which it means that 11.7 moles are present in 1 liter.

So we took 25 mL and we have to know how many moles, do we have now.

1000 mL 11.7 moles

25 mL (25 . 11.7)/1000 = 0.2925 moles

This are the moles, we add to the solution where the [HCl] is 3.25 M

In 1000 mL __ we have __ 3.25moles

175 mL we have __ (175 . 3.25)/1000 = 0.56875 moles

Total moles: 0.2925 + 0.56875 = 0.861 moles

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i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)