Answer:
Kw = 2.88 × 10⁻¹⁵
Explanation:
Let's consider the dissociation of water.
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
The equilibrium constant Kw is:
Kw = [H⁺].[OH⁻]
If pH = 7.27, we can find [H⁺]:
pH = -log [H⁺]
H⁺ = anti log (-pH) = anti log (-7.27) = 5.37 × 10⁻⁸ M
According to the balanced equation, 1 mole of H⁺ is produced per mole of OH⁻. So, [H⁺] = [OH⁻] = 5.37 × 10⁻⁸ M
Then,
Kw = [H⁺].[OH⁻]= (5.37 × 10⁻⁸)² = 2.88 × 10⁻¹⁵
Answer: the sum of the partial pressures of the individual gases.
Explanation:
According to Dalton's Law of partial pressure, the total pressure of a mixture of gases is equal to the sum of the partial pressures which each individual gas would exert if it were confined alone in the volume occupied by the mixture.
Hence, Ptotal = P1+ P2
where Ptotal is the total pressure
P1 and P2 are the partial pressures exerted seperately by the individual gases 1 and 2 that make up the mixture.
Answer:
c.boron-11
Explanation:
The atomic mass of boron is 10.81 u.
And 10.81 u is a lot closer to 11u than it is to 10u, so there must be more of boron-11.
To convince you fully, we can also do a simple calculation to find the exact proportion of boron-11 using the following formula:
(10u)(x)+(11u)(1−x)100%=10.81u
Where u is the unit for atomic mass and x is the proportion of boron-10 out of the total boron abundance which is 100%.
Solving for x we get:
11u−ux=10.81u
0.19u=ux
x=0.19
1−x=0.81
And thus the abundance of boron-11 is roughly 81%.
Answer:
The 2 ml and 2.0 ml is the same thing.
Answer:
Air
Explanation:
It takes up space/ the rest do not
