25cm^3 of 0.1M NaOH is reacted with 0.01M HCl until the equivalence point is reached. What volume of HCl was required to be added?
0.025 dm^3 x 0.1 mol dm^-3 = 0.0025 molsince mols must be equal:mols of HCl = 0.0025/0.01 =250cm^3To get to the answer I would first check the student was first able to identify the key words and numbers in the question, and then able to explain them, eg. equivalence pointWould then go through suitable equations eg. n=CV what they mean and how to use them.Then unit checks to make sure they are converted correctly, to get to the correct answersFinally how to use units to check answers to give the student more confidence.
GW
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