Question
What do the spectral lines represent?
Answer:
Spectral lines is defined by quantum mechanics in terms of energy levels of ions, molecules, and atoms. When electrons move from a higher level to lower one, photons are emitted and an emission line can be seen in the spectrum. As electrons jump down to the n=2 orbit, they emit photons of specific frequency (hence colour) that can be seen as emission lines in the visible part of spectrum.
Explanation:
<span>pH = pKa + log ([base]/[acid]) = -log (3.5 x 10^-4) + log (0.040/.020) = 3.46 - 0.30 = 3.16</span>
Answer:
b) heating, cooling
Explanation:
Heating will favour dissolution (it helps dissolving faster).
Cooling helps in crystallization.
When air descends it compresses. When the air compresses the molecules in the air knock into each other more often, increasing the tempertature.
Hope this helps
Answer:
The yield of the product in gram is 
Explanation:
Given that:
the molecular mass weight of the product = 96.2 g/mol
the molecular mass of the reagent (3S)-2,2,-dibromo-3,4-dimethylpentane is 257.997 g
given that the millimoles of the reagent = 2,7 millimoles = 
We know that:
Number of moles = mass/molar mass
Then:
mass = 0.697
Theoretical yield = (number of moles of the product/ number of moles of reactant) × 100
i.e
Theoretical yield = 
where;
and 
Theoretical yield = 
Given that the theoretical yield = 100%
Then:
where,
= derived weight of the product
the molecular mass of the derived product
the molecular mass of the reagent
= weight in a gram of the reagent
