Final answer:
The percentage by weight of acetic acid in vinegar can be calculated using the information provided. In this case, since the given solution is a 5% by mass solution of acetic acid in water, the percent by weight of acetic acid in the vinegar would be 5%.
Step-by-step explanation:
The percentage by weight of acetic acid in vinegar can be calculated using the information provided. In the given example, white vinegar is a 5.0% by mass solution of acetic acid in water. To calculate the percent by weight, we need to know the mass of acetic acid in a given amount of vinegar. Assuming the density of vinegar is 1 g/mL, we can convert the volume of the vinegar to grams by using the density. For example, if we have 100 mL of vinegar, the mass of the vinegar would be 100 g. Since the vinegar is a 5% solution, 5% of the mass is acetic acid. Therefore, the percent by weight of acetic acid in the vinegar would be 5%.