Answer:
a. Are potentially dangerous and should not be worn.
The pressure of diver = atmospheric pressure + water pressure
atmospheric pressure = 750 mmHg (as given) = 750 / 760 atm = 0.987 atm
Water pressure is
P = hρg
where
h = height of water = 38 ft
1 ft = 0.3048
38 ft = 11.58 m
ρ = density = 1000 Kg / m³
g = gravitational constant = 9.81 m/s2
P = 11.58 X 1000 X 9.81 = 113599.8 Kg / m s^2 Or N /m^2
1 N / m^2 = 1 pa = 9.869 X 10^-6 atm
P = 113599.8 Pa = 1.12 atm
Total pressure = 1.12 + 0.987 atm = 2.107 atm = 2.1 atm (two significant figures)
Answer: 5.48
Explanation:
pH is the negative logarithm of hydrogen ion concentration in a solution.
Mathematically, pH = - log(H+)
where H+ represent the concentration of hydrogen ion
So, to get the pH of the solution with [H +] = 3.25×10-6 M:
Apply, pH = -log(H+)
pH = - log (3.25×10-6 M)
pH = - ( -5.48)
(Note that the minus signs will cancel out each other)
Therefore pH = 5.48
Now we know that the pH of the solution with hydrogen ion concentration of 3.25×10-6 M is 5.48 (i.e slightly acidic)
Thus, we can finally say 5.48 is the pH of the solution within a solution with pH = 4.50
The reaction is:
X + Y → W + Z
Chemical energy of reactant X = 199.3 J = Ux
Chemical energy of reactant Y = 272.3 J = Uy
Chemical energy of Product W = 41.9 J = Uw
Chemical energy of Product Z = ? = Uz
Where reaction loses energy = 111.6 J = ΔU
By using the equation:
(Ux + Uy) – (Uw + Uz) = ΔU
Ux + Uy – Uw – Uz = ΔU
Uz = Ux + Uy – Uw –ΔU
Uz = 199.3 + 272.3 – 41.9 – 111.6
Uz = 318.1 J
Product Z must contain 318.1 J chemical energy.
Answer:
See explanation
Explanation:
In an atom, the inner electrons may shield the outer electrons from the attractive force of the nucleus. We, refer to this phenomenon as the <u><em>shielding effect</em></u>, It is defined as a decrease in the magnitude of attraction between an electron and the nucleus of an atom having more than one electron shell (energy level).
Shielding effect increases down the group due to addition of more shells but decreases across the period due to the increase in the size of the nuclear charge.
As the magnitude of shielding increases down the group, ionization of electrons becomes easier and the first ionization energies of elements decreases as we move down the group. Since shielding effect decreases across the period, the first ionization energies of elements increases across the period.
