The density has been given as the mass of the substance per volume of the solution. The mass of citric acid in the bottle has been 1.22 grams.
<h3>What is percent mass?</h3>
Percent mass can be given as the mass of substance in the total mass of the solution.
The volume of the face serum has been 250 mL, and the density is 0.979 g/mL.
The mass of face serum in the bottle has been:

The total mass of face serum has been 244.75 grams.
The percent mass of citric acid in face serum is 0.5%. This states the presence of 0.5-gram citric acids in 100 grams sample.
The mass of citric acid in the face serum sample is given as:

The mass of citric acid present in 250 mL serum sample has been 1.22 grams.
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brainly.com/question/5394922
Composer and performer of Old Occitan lyric poetryduring the High Middle Ages (1100–1350). Since the word troubadour is etymologically masculine, a female troubadour is usually called a trobairitz.
Answer:
A. True
B. False
Explanation:
Reaction between hypochlorous acid and ammonia does not yields a Ph value of 7.00 , this value is defined to water and no other reaction can yield exactly this Ph value. The acid reaction will give a Ph value below 7 while a base reaction will give Ph value of above 7.