The characteristics flame test color of metal ions are because of the atomic emission spectra.
When an atom absorbs a particular wavelength radiation, the electrons within it, move from lower energy level to the higher level of energy. Such a procedure is called absorption. When this stimulated electron to come back to its ground state, it loses energy in particular color on the basis of the frequency of the absorbed radiation. Such a procedure is called emission.
As an atom exhibit, distinct levels of energy, the level close to the nucleus possess less energy in comparison to the level, which is far from the nucleus. So, electrons move from lower energy level to the higher level by attaining particular energy, and after excitation, it comes back from high energy level to a low energy level with the emission of light.
According to Planck's concept, there is a specific difference of energy between the two energy level, so such energy difference is quantized. Only those radiation are absorbed, which are equivalent to the difference of energy between the two levels.
V = nRT/P
V = 0.685 mol*(.0821 L*atm/K*mol)*273 K/1 atm
Answer:
Explanation:
Heat required to convert ice to ice at 0⁰C
= mass x specific heat x rise in temperature
= 18 x 2.09 x 20
= 752.4 J .
heat required to convert ice at 0⁰C to water at 0⁰C
mass x latent heat of fusion
= 18 x 336
= 6048 J
Heat required to increase the temperature of water to 100⁰C
= 18 x 4.2 x 100
= 7560 J
Total heat required
7560 + 6048 + 752.4
= 14360.4 J
There are two ways to solve this problem. We can use the ICE method which is tedious and lengthy or use the Henderson–Hasselbalch equation. This equation relates pH and the concentration of the ions in the solution. It is expressed as
pH = pKa + log [A]/[HA]
where pKa = - log [Ka]
[A] is the concentration of the conjugate base
[HA] is the concentration of the acid
Given:
Ka = 1.8x10^-5
NaOH added = 0.015 mol
HC2H3O2 = 0.1 mol
NaC2H3O2 = 0.1 mol
Solution:
pKa = - log ( 1.8x10^-5) = 4.74
[A] = 0.015 mol + 0.100 mol = .115 moles
[HA] = .1 - 0.015 = 0.085 moles
pH = 4.74 + log (.115/0.085)
pH = 4.87
