What should be done immediately after the sample is added in the Speedy Moisture Test?

The correct action immediately after the sample is added in the Speedy Moisture Test is to cap the vessel upside down. This step is crucial because it ensures that any excess moisture in the sample is transferred to the reagent, allowing for an accurate measurement of the moisture content. By capping the vessel upside down, you also prevent the escape of volatile moisture and ensure that the reaction proceeds optimally, leading to reliable results.

In contrast, sealing the vessel tightly does not facilitate the necessary reactions among the components in the test; simply adding more reagent is unnecessary since the appropriate amount is already included; and shaking the vessel could disrupt the process or lead to an inaccurate reading as it might affect the stabilization of the solution that is crucial for accurate results. Thus, capping upside down is essential for the integrity of the test.