Acids and Spectral Lines
39 g of an acid was dissolved in water to form a solution whose volume was 1 liter. Similarly, 40 g of NaOH was dissolved in water to form a 1 liter solution.
Both these solutions reacted completely with each other. If the molar mass of the acid is 82 g, find the basicity of the acid and approximate it to the nearest integer.
If this number is multiplied by 3, and the two resulting values (the number itself and the number obtained when it is multiplied by 3) are considered to be the excited state and the relaxed state of a particular atom.
Calculate the number of spectral lines that can be obtained in such a transition.
Image Credit: Flickr Reginald Van de Velde .
The answer is 10.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
For this particular problem, it can be solved using one of the principles that is commonly used in titrimetry which is the "Law of Chemical Equivalents"
Here the number of equivalents of the acid is equal to the number of equivalents of NaOH,
Equivalents of NaOH = "moles in solution" times "acidity of the base"
Substituting values, Equivalents = 1
Similarly for the acid, Equivalents = "moles in the solution" times "basicity of the acid"
Assume basicity to be "x" and substitute values.
8 2 3 9 x = 1
On solving this equation we get the value to be approximately equal to 2.
Hence basicity is 2.
Multiplying this number by 3 gives us the number 6.
Implying, Excited state = 6 ; Relaxed state = 2
Number of spectral lines is
∑ i = 1 6 − 2 = ∑ i = 1 4 = 10