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help with chemistry titrations Watch

    • Thread Starter

    an impure sample of magnesium carbonate was dissolved in 30.0cm3 of 0.100 mol dm-3 hydrochloric acid. the magnesium carbonate reacted with this acid according to the equation : mgCo3 + 2HCL - MgCL2 + CO2 + H20
    leaving some of the acid unreacted. this excess acid was titrated with 0.10 mol dm-3 sodium hydroxide solution and 12.3cm3 was required for neutralisation. the results were used to find the percentage purity of the magnesium carbonate.
    a) calculate the number of moles of hydrochloric acid originally added to the magnesium carbonate
    b) calculate the number of moles of sodium hydroxide which neutralised the unreacted hcl
    c) how many moles of hcl was left at the end of the reaction
    d) using your answers from part a and b, calculate the number of moles of hcl which reacted with the magnesium carbonate
    e) what volume of hcl added reacted with with the magnesium carbonate
    f) how many moles of magnesium carbonate reacted with this hcl
    g) what mass of magnesium carbonate was in the sample
    h) the impure sample weighed 0.124g what was the percentage by mass of magnesium carbonate in it?

    thank you

    What have you done so far?
    • Thread Starter

    (Original post by Ze Witcher)
    What have you done so far?
    i dont understand any of it
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