There are four major methods of purification in the chemistry laboratory. which of the given techniques is not one of the four most common methods for separation and purification?

The four major methods of separation and purification techniques in the laboratory are as follows,

1. Chromatography

2. Recrystallization,

3. Distillation, and

4. Extraction

Spectroscopy however is not a common separation and purification method

Explanation:

Mass spectrometer separates ions in respect to the ratio of their mass to the their charge and are then detected based on their relative abundance this technique is used in the analysis of biomolecules

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2