# Finding the concentration of a solution

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• Created by: Mackenzie
• Created on: 19-12-12 12:09

## Concentration

Write the equation - balance it

( HCl + NaOH --> NaCl + H2O )

Look at the numbers in the front of the acid and base to see how many moles of each there are

There are no numbers(in this case) so 1 mole each

Meaning: If 0.5 moles of base are used then 0.5 moles of acid are needed - ratio 1:1

Use info you know for the base to calculate how many moles of the base were used

No.Moles = concentration x volume (cm3)

Number of moles in acid = same

calculate concentration:

concentration = no.moles / volume

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## Performing titrations to find concentration of HCl

Meausre known volume of alkali into conical flask - use burette or graduated pipette

Add acid from a filled burette - slowly until indicator changes colour

Record volumem of acid used

Repeat experiment but add the acid drop by drop when you get close to the volume added the first time - gives you exact volume

Repeat to get 2 values and make an average

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