Explanation:

The value of
:
![K_w=[H^+][OH^-]](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BOH%5E-%5D)
a. pOH = 3.51
The sum of pH and pOH is equal to 14.
pH + pOH = 14 (at 25°C)
pH = 14 - 3.51 = 10.49
The pH of the solution is defined as negative logarithm of hydrogen ion concentration in solution.
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
![10.49=-\log[H^+]](https://tex.z-dn.net/?f=10.49%3D-%5Clog%5BH%5E%2B%5D)
![[H^+]=3.2\times 10^{-11}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D3.2%5Ctimes%2010%5E%7B-11%7D)
is the
concentration for an aqueous solution with pOH = 3.51 at 25°C.
b.
At a certain temperature, the pH of a neutral solution is 7.56.
Neutral solution means that concentration of hydrogen ion and hydroxide ions are equal.
![[H^+]=[OH^-]](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D%5BOH%5E-%5D)
![7.56=-\log[H^+]](https://tex.z-dn.net/?f=7.56%3D-%5Clog%5BH%5E%2B%5D)
![[H^+]=2.754\times 10^{-8} M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D2.754%5Ctimes%2010%5E%7B-8%7D%20M)
The value of
at at this temperature:
![K_w=[H^+][OH^-]](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BOH%5E-%5D)
![K_w=[H^+][H^+]](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BH%5E%2B%5D)

The value of
at at this temperature is
.
Moles KClO₃ = 0.239
<h3>Further explanation</h3>
Given
Reaction
2KClO₃(s) ⇒2KCl(s) + 3O₂(g)
P water = 23.8 mmHg
P tot = 758 mmHg
V = 9.07 L
T = 25 + 273 = 298 K
Required
moles of KClO₃
Solution
P tot = P O₂ + P water
P O₂ = P tot - P water
P O₂ = 758 - 23.8
P O₂ = 734.2 mmHg = 0.966 atm
moles O₂ :
n = PV/RT
n = 0.966 x 9.07 / 0.082 x 298
n = 0.358
From equation, mol ratio KClO₃ : O₂ = 2 : 3, so mol KClO₃ :
= 2/3 x mol O₂
= 2/3 x 0.358
= 0.239
The two strands must be separated like the two sides of a zipper, by breaking the weak hydrogen bonds that link the paired bases.
<u>Explanation:</u>
- A double helix structure formed by two polypeptide chains is separated like the two sides of a zipper. A zipper is formed by breaking the weak hydrogen bonds that link the paired bases. During replication, an enzyme "Helicase" travels down the DNA and splits the chain and it forms 2 separate strands.
- The two DNA strand which has the same sequence must be separated like the two sides of a zipper by breaking weak hydrogen bases. During base pair-rule, the strand are unzipped and each strands is copied.