The first one is C. Hope this helps!! If you need anymore help just message me and I will try to get back to you quickly and help in any way i can!
The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
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NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
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KOH
- it is a strong base (pH=14)
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He needs to use HF (Hydrogen fluoride) to decrease the pH.
Answer:
4.6s
Explanation:
v=u+at
0=22.5+(-9.8)t
-22.5=-9.8t
t=-22.5/-9.8
t=2.295 s
The total time will double
2.295×2=4.59s
=4.6s
