Chem stoichometry help

[ahs4n]

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What would be the pH if .38 g of Fe+3 reacted with 25 L of water assuming only the following equation contributed to pH.

Fe+3 + H2O yields 3H+ + Fe(OH)3

 

[ahs4n]

Sorry, but I was wondering why the beginning step necessitated that you divide the .38 grams by the 25 L of water

 

[loveoforganic]

pH = -log[(0.38 grams Fe3+)*(1 mole Fe3+/55.845 grams Fe3+)*(3 mole H+/1 mole Fe3+) / (25 L)]

You have to divide by 25 L because molarity (concentration) is given in units of moles / 1 L, not moles per 25 L

 

[funsmith]

Very nice!