A. HCl:
pH= -log [H3O+]
PH=-log (0.200)
= 0.699
poH= 14-0.699
= 13.301
b. NaOH:
PoH= -log [OH-]
= -log (0.0143)
= 1.845
pH= 14-poH
= 14- 1.845
= 12.16
c. HNO3:
PH= -log[H3O+]
=-log(3.0)
= -0.4771
poH= 14-pH
= 14-9-0.4771
= 14.4771
pH= -0.4771, poH= 14.4771
d. [Ca(OH)2] = 0.0031M
[OH-]= 2X0.0031
[OH-] = 0.0062M
PoH= - log[OH-]
=-log(0.0062)
=-log(6.2x10-3)
=-(-2.21)
= 2.21
PH=14-poH
=14-2.21
=11.79
POH=2.21, PH= 11.79
The amount left after 20 years = 154.15 mg
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually radioactive elements have an unstable atomic nucleus.
The main particles are emitted by radioactive elements so that they generally decay are alpha (α), beta (β) and gamma (γ) particles
The decay formula for isotope :

Then for t=20 years, the amount left :

Organic Chemistry- Substances only found in living organisms.
Physical Chemistry- Structure of physical compounds and the amount of energy they have.
Inorganic Chemistry- Study of carbon containing compounds.
Answer: The amount of energy lost by the metal is equal to the amount of energy gained by the water
Explanation:
I think the answer might be B but i’m not positive