Final answer:
To find the weight of a substance in a container, multiply the density (0.789 g/mL) by the container's volume (75 mL), resulting in a mass of 59.175 grams for the substance filling the container.
Step-by-step explanation:
To calculate the weight of a substance that fills a container with a known volume, we use the concept of density. The density of a substance is its mass per unit volume, typically expressed in grams per milliliter (g/mL) in the metric system.
In this case, the density of the substance is given as 0.789 g/mL at 20°C, and the volume of the container is 75 mL. To find the mass (weight) that the substance will have when it fills this container, we multiply the density of the substance by the volume of the container:
Mass = Density × Volume = 0.789 g/mL × 75 mL
After calculating, we find that the mass of the substance that fills the container is:
Mass = 59.175 g