How many moles of HCl need to be added to 200.0 mL of a 0.200 M solution of NaF to make a buffer with a pH of 2.80? (Ka for HF is 6.8 × 10⁻⁴)

you gotta add the following molecules so we can give u an answer

explanation:

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.