Answer:
0.2 M.
Explanation:
- For the acid-base neutralization, we have the role:
The no. of millimoles of acid is equal to that of the base at the neutralization.
<em>∴ (XMV) KOH = (XMV) H₂SO₄.</em>
X is the no. of reproducible H⁺ (for acid) or OH⁻ (for base),
M is the molarity.
V is the volume.
X = 1, M = 0.5 M, V = 38.74 mL.
X = 2, M = ??? M, V = 50.0 mL.
∴ M of H₂SO₄ = (XMV) KOH/(XV) H₂SO₄ = (1)(0.5 M)(38.74 mL)/(2)(50.0 mL) = 0.1937 M ≅ 0.2 M.
Answer:
ΔG = - 442.5 KJ/mol
Explanation:
Data Given
delta H = -472 kJ/mol
delta S = -108 J/mol K
So,
delta S = -0.108 J/mol K
delta Gº = ?
Solution:
The answer will be calculated by the following equation for the Gibbs free energy
G = H - TS
Where
G = Gibbs free energy
H = enthalpy of a system (heat
T = temperature
S = entropy
So the change in the Gibbs free energy at constant temperature can be written as
ΔG = ΔH - TΔS . . . . . . (1)
Where
ΔG = Change in Gibb’s free energy
ΔH = Change in enthalpy of a system
ΔS = Change in entropy
if system have standard temperature then
T = 273.15 K
Now,
put values in equation 1
ΔG = (-472 kJ/mol) - 273.15 K (-0.108 KJ/mol K)
ΔG = (-472 kJ/mol) - (-29.5 KJ/mol)
ΔG = -472 kJ/mol + 29.5 KJ/mol
ΔG = - 442.5 KJ/mol
Answer:
The wavelength of the incoming photon is 172.8 nm
Explanation:
The wavelength of the incoming photon can be calculated with the photoelectric equation:
(1)
Where:
KE: is the kinetic energy of the electron
h: is Planck's constant = 6.62x10⁻³⁴ J.s
c: is the speed of light = 3.00x10⁸ m/s
: is the wavelength of the photon =?
Φ: is the work function of the surface (Iron) = 4.5 eV
The kinetic energy of the electron is given by:
(2)
Where:
p: is the linear momentum = h/λ
m: is the electron's mass = 9.1x10⁻³¹ kg
: is the wavelength of the electron = 0.75 nm = 0.75x10⁻⁹ m
Hence, the wavelength of the photon is:
Therefore, the wavelength of the incoming photon is 172.8 nm.
I hope it helps you!
Answer:easterly winds blow from east to west and westerly winds blow from west to east
Explanation:
