How do you find the number of moles for your unknown?

Question

Chemistry

Sheldon Vega

3 July, 23:58

How do you find the number of moles for your unknown?

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Answers (2)

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India Robertson · Answer 1

The formula used for titrations has general application for complete reactions and can be used here. However, a direct chemical thinking is even simpler. 15 ml of a 0.21M NaOH solution contain 15X0.21 mEq (milliequivalents, see referenced answer above) of NaOH and by definition require the same number of equivalents to react completely with the unknown compound (X). Therefore : Eq (X) = 25/0.21 x 15 = 7.95g

Leland Bowen · Answer 2

The formula used for titrations has general application for complete reactions and can be used here. However, a direct chemical thinking is even simpler. 15 ml of a 0.21M NaOH solution contain 15X0.21 mEq (milliequivalents, see referenced answer above) of NaOH and by definition require the same number of equivalents to react completely with the unknown compound (X). Therefore : Eq (X) = 25/0.21 x 15 = 7.95g

The equivalent of X is 7.94g and so is is the gram mole since X is monovalent.