Answer:
6
Explanation:
Significant figures:
The given measurement have six significant figures 120.090.
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.
Zero between the non zero digits are consider significant like 104 consist of three significant figures.
The zeros at the right side e.g 2400 are also significant. There are four significant figures are present.
In 120.090 the zero before and after 9 are also significant.
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Answer: He could add a base to the pool to neutralize the acid.
Explanation:
Chlorine is used to disinfect the pools as it produces hypochlorous acid in water. This hypochlorous acid is unstable and gives hydrochloric acid and nascent oxygen which is used to disinfect.

The excess acid is neutralized by adding base which produces salt and water and thus decrease the acidity.

Adding more acid would increase the acidity further.
Answer:
b. changing the compound changes the absorbance behavior.
Explanation:
- Option a) would be akin to modifying the <em>path length</em>, b.
- Option b) would involve using a different solute, as such, there would be another <em>molar absortivity</em>, ε.
- Option c) would decrease the<em> concentration</em> (c) of the solute, which would explain why the absorbance would decrease as well.
Answer:
B.
Explanation:
Buffer has equal concentrations of A- and HA.
B. when [F -] is equal to [HF]