<span>[H3O+] = 10^(-pH) = 10^(-4.20) = 6.3 x 10^-5 M
pOH = 14 - pH = 14 - 4.20 = 9.80
[OH-] = 10^(-pOH) = 10^(-9.80) = 1.6 x 10^-10 M
</span>
Answer:
11552.45 years
Explanation:
Given that:
Half life = 5730 years
Where, k is rate constant
So,
The rate constant, k = 0.00012 years⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given that:
The rate constant, k = 0.00012 years⁻¹
Initial concentration
= 160.0 counts/min
Final concentration
= 40.0 counts/min
Time = ?
Applying in the above equation, we get that:-

<span>Kind of substance besides water:
The best example of hydrogen bonding excluding water is DNA. The two strands of polymers are connected by hydrogen bonds between the nucleotide bases</span>.