Work out the mass of impure magnesium carbonate used in the experiment.
What can be seen in the flask as the reaction goes on?
Which apparatus should be used to prepare V?
Name a safety device that should be attached to the pipette, and say why it is used.
What colour change does methyl orange show at the end-point? The colour goes from .......... to .......... .
From the diagrams, finish the results table. Put a tick ($\checkmark$) beside the most reliable titration results. Using those results, the average volume of $0.100\,\text{mol dm}^{-3}$ sodium hydroxide needed is ______ $\text{cm}^3$.
Determine the moles of sodium hydroxide in the average volume of $0.100\,\text{mol dm}^{-3}$ sodium hydroxide.
Using the equation below and your value from (f), deduce the amount of hydrochloric acid present in $25.0\,\text{cm}^3$ of V. $\text{NaOH} + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O}$
Find the moles of hydrochloric acid in $250\,\text{cm}^3$ of V.
Use your answer to (h) and subtract it from $0.0500$ to find how many moles of hydrochloric acid react with the magnesium carbonate sample.
Using the equation below and your answer to (i), work out the moles of magnesium carbonate in the sample. $\text{MgCO}_3 + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2\text{O} + \text{CO}_2$
Calculate the mass of magnesium carbonate in the sample. [The relative formula mass of magnesium carbonate is $84$.]
Using your values from (a) and (k)(i), determine the percentage purity of the magnesium carbonate.