Answer:
1.59 x 10⁻²⁵ J.
Explanation:
- The energy of a photon is calculated Planck - Einstein's equation:
E = h ν
, where
E is the energy of the photon,
h is Planck's constant <em>(h = 6.626 x 10
⁻³⁴ J.s)</em>
ν is the frequency of the photon
-
There is a relation between the frequency (ν
) and wave length (λ).
λ.ν = c,
where c is the speed of light in vacuum (c = 3
.0 x 10
⁸ m/s).
λ = 125 cm = 1.25 m.
<em>Now, E = h.c/λ.</em>
∴ E = h.c/λ = (6.626 x 10
⁻³⁴ J.s) (3
.0 x 10
⁸ m/s) / (1.25 m) = 1.59 x 10⁻²⁵ J.
Among formic acid (HCOOH ) and sulfuric acid (H₂SO₄), formic acid is the weak acid. Acidic strength of any acid is the tendency of that acid to loose proton. Among these two acids formic acid has a pKa value of 3.74 greater than that of sulfuric acid i.e. -10. Remember! Greater the pKa value of acid weaker is that acid and vice versa. Below I have drawn the Ionization of both acids to corresponding conjugate bases and protons. The structures below with charges are drawn in order to explain the reason for strength. As it is seen in charged structure of formic acid, there is one positive charge on carbon next to oxygen carrying proton. The electron density is shifted toward carbon as it is electron deficient and demands more electron hence, attracting electron density from oxygen and making the oxygen hydrogen bond more polar. While, in case of sulfuric acid it is depicted that Sulfur attached to oxygen containing proton has 2+ charge, means more electron deficient as compared to carbon of formic acid, hence, more electron demanding and strongly attracting electrons from oxygen and making the oxygen hydrogen bond very polar and highly ionizable.

Answer:
2. 181.25 K.
3. 0.04 atm.
Explanation:
2. Determination of the temperature.
Number of mole (n) = 2.1 moles
Pressure (P) = 1.25 atm
Volume (V) = 25 L
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =?
The temperature can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
1.25 × 25 = 2.1 × 0.0821 × T
31.25 = 0.17241 × T
Divide both side by 0.17241
T = 31.25 / 0.17241
T = 181.25 K
Thus, the temperature is 181.25 K.
3. Determination of the pressure.
Number of mole (n) = 10 moles
Volume (V) = 5000 L
Temperature (T) = –10 °C = –10 °C + 273 = 263 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =?
The pressure can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
P × 5000 = 10 × 0.0821 × 263
P × 5000 = 215.923
Divide both side by 5000
P = 215.923 / 5000
P = 0.04 atm
Thus, the pressure is 0.04 atm