The percentage of silver in a solid sample is determined gravimetrically by converting the silver to $\ce{Ag+(aq)}$ and precipitating it as silver chloride. Failure to do which of the following could cause errors in the analysis?

1. Account for the mass of the weighing paper when determining the mass of the sample
2. Measure the temperature during the precipitation reaction
3. Wash the precipitate
4. Heat the $\ce{AgCl}$ precipitate to constant mass

If the weighing paper is not taken into account, we would be overestimating the mass of the sample.

Measuring the temperature is not necessary and does not affect the outcome.

Washing the precipitate is necesssary to make sure all of the ions are in solution rather than attached to the precipitate.

Heating the precipitate removes water molecules so that we can have as pure of a precipitate as possible.