It helps our eyes to see better. For example: If you can't read a book because you see that is blurry, you might need glasses to see it much clearer
Answer:
241 nm, it is UV light range
Explanation:
The minimum energy needed required to break the oxygen-oxygen bond = 495 kJ/mol
Energy needed for 1 molecule of oxygen = 495 × 10³ J / avogadro's constant = 495 × 10³ J / ( 6.02 × 10²³) = 8.223 × 10⁻¹⁹ J
Energy = hv
where h = Planck constant = 6.626 × 10 ⁻³⁴ m²kg/s and v = frequency
c speed of light = vλ
c / λ = v
E = hc / λ
λ = hc / E = (6.626 × 10 ⁻³⁴ m²kg/s × 3.0 × 10 ⁸ m/s) / (8.223 × 10⁻¹⁹ J) = 2.41 × 10⁻⁷m = 241 nm
UV light wavelength is between 400 nm - 10 nm
The balanced chemical reaction is given as:
2H2S (g) + 3O2 (g) 2SO2 (g) + 2H2O (g)
We are given the volume at STP of H2S to be used for the reaction. This would be the starting point for the calculations. We do as follows:
45.0 L H2S ( 1 mol / 22.4 L) ( 3 mol O2 / 2 mol H2S ) ( 22.4 L / 1 mol ) = 67.5 L O2 needed
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Answer:
pH = 8.477
Explanation:
∴ ni 0.3 - -
nf - 0.3 0.3
∴ ni 0.50 - 0.3
nf 0.5 - X X 0.3 + X
∴ Ka = 2.0 E-9 = ([H3O+]*[OBr-]) / [HOBr]
⇒ Ka = 2.0 E-9 = ((X/1L)*(0.3 + X)/1 L) / ((0.5 - X)/1L)
⇒ 2.0 E-9 = ( 0.3X + X² ) / (0.5 - X)
⇒ X² + 0.3X - 1 E-9 = 0
⇒ X = 4.333 E-9 M
according Henderson-Hauselbach:
- pH = pk + Log [A-] / [HA]
∴ [OBr-] = 0.3 mol/ 1 L + 4.333 E-9 M = 0.300 M
∴ [HOBr] = 0.5 mol / 1 L - 4.33 E-9 M = 0.500 M
∴ pKa = - log Ka = - Log ( 2.0 E-9 ) = 8.6989
⇒ pH = 8.6989 + Log ( 0.300/0.500 )
⇒ pH = 8.477
