Which of the following substances is most acidic?
a
rain water with a pH of 5.5
b
blood with a pH of 7.4
c
sea water with a pH of 8.0
d
bleach with a pH of 13.0
The correct answer is a) rainwater with a pH of 5.5. A lower pH indicates higher acidity, and a pH of 5.5 is lower than the pH of blood (7.4), sea water (8.0), and bleach (13.0).
To determine which of the substances is the most acidic, we need to compare their pH values. The pH scale ranges from 0 to 14, with 7 being neutral. Any substance with a pH less than 7 is considered acidic. So, among the given options:
a) Rainwater with a pH of 5.5: This substance has a pH below 7, indicating that it is acidic.
b) Blood with a pH of 7.4: Blood has a pH slightly above 7, making it slightly alkaline or basic, not acidic.
c) Sea water with a pH of 8.0: Sea water has a pH higher than 7, which means it is basic, not acidic.
d) Bleach with a pH of 13.0: Bleach has a very high pH, much greater than 7, indicating that it is highly alkaline or basic. It is not acidic.
Therefore, the most acidic substance among the options provided is rainwater with a pH of 5.5 (option a).
To determine which substance is the most acidic, we can compare their pH values. The pH scale ranges from 0 to 14, with lower values indicating higher acidity.
In this case, let's compare the pH values of the substances:
a) Rainwater with a pH of 5.5
b) Blood with a pH of 7.4
c) Sea water with a pH of 8.0
d) Bleach with a pH of 13.0
Among these options, the substance with the lowest pH value is rainwater with a pH of 5.5. Therefore, rainwater is the most acidic substance in this set.