Describe and explain the possible effects on your results of the following exper

Question

Describe and explain the possible effects on your results of the following experimental errors.

a. You allowed your chromatogram to develop too long and you couldn’t find the solvent front.

b.The lab assistant who prepared the developing solvent mistakenly used aqueous ammonia in place of acetic acid.

c.You used an opened melting-point capillary rather than a Drummond Microcap to apply the spots

What would be the effect on the reaction rate if 10 mL of DMF were used for the reaction instead of 5 mL? Why?

Explanation / Answer

a. You allowed your chromatogram to develop too long and you couldn’t find the solvent front.

You are allowed to develop a chromotogram too long but the solvent should not overflow the plate.if you allow it to overflow then you cant find the solvent front.

b.The lab assistant who prepared the developing solvent mistakenly used aqueous ammonia in place of acetic acid.

Acetic acid is highly polar solvent. so aqueous ammonia is generally used to elute acidic compounds. silica gel is acidic if you use ammonia it will neutralise the silia gel and you will see that your spots moved longer.

c.You used an opened melting-point capillary rather than a Drummond Microcap to apply the spots

If you use opened melting point capillary or drummond microcap, there wont be any change in the spot height. Only difference we will see is the spreaded spot in case of meling point capillary

What would be the effect on the reaction rate if 10 mL of DMF were used for the reaction instead of 5 mL? Why?

Dilution always reduce the rate of reaction. During dilution, that means if you use 10 ml of DMF instead of 5 ml, the molecules will not be close together to form the product. So, it will take more time to give the products.

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.