Why do you think scientists add excess of one or more chemicals when performing a reaction rather than combine the exact stoichiometric ratio?

The mistake in the experiment is diminished in that you might be uncertain in your estimation of both materials. With just a single estimation, there are fewer blunders. A researcher will pick constraining and abundance materials as a rule by their simplicity of estimation. A strong is more effortlessly measured than a gas, for instance. In burning responses, oxygen gas is in abundance, as it is not effectively checked all through the response.