Final answer:
To determine the volume of isopropanol in a 79.0 ml sample of a 78.5% (v/v) solution, multiply the total volume by the percentage (expressed as a decimal) to get approximately 62.015 milliliters of isopropanol.
Step-by-step explanation:
The question is asking to calculate the volume of isopropanol in a given volume of solution, based on its percentage concentration by volume. Specifically, we need to find out how many milliliters of isopropanol are present in a 79.0 ml sample of 78.5% (v/v) isopropanol in water. To find this, we use the formula:
Volume of isopropanol = (Volume of solution × Percentage of isopropanol) / 100
By plugging in the given values:
Volume of isopropanol = (79.0 mL × 78.5%) / 100
This calculation gives us:
Volume of isopropanol = (79.0 mL × 0.785)
After performing the multiplication, we find that there are approximately 62.015 milliliters of isopropanol in the rubbing alcohol solution.