CHE 110: PRACTICAL INTRODUCTORY ORGANIC CHEMISTRY PART 2 QUESTIONS AND ANSWERS

QUESTIONS TO SOLVE UNDER CHEM PRACTICALS

1) I am an Organic compound/substance, when I am heated with sodium metal, I  am converted to a sodium salt. My sodium salt reacts with ferrous ammonium sulfate

[Fe(NH4)2(SO4)2 to yield sodium ferrocyanide [Na4Fe(CN)] which further reacts with

ferric salts to give a deep blue color.

a) Who am I

b) Write a balanced chemical equation my sodium salt and ferrous ammonium sulfate

c) Write an equation between sodium ferrocyanide and ferric salt

d) What is responsible for the deep blue coloration?

2. Mention THREE (3) glasswares or apparatus in the chemistry laboartory and state their uses

                                              SOLUTIONS TO THE ABOVE QUESTIONS

1. 

a) The organic compound is likely a carboxylic acid or a derivative of it, possibly sodium acetate or sodium formate.

b) CH3COO-Na+ + Fe(NH4)2(SO4)2 → Na4Fe(CN)6 + 2(NH4)2SO4 + 2H2O + 2CO2

c) Na4Fe(CN)6 + 2FeCl3 → 2Na[Fe(CN)6] + 2FeCl2

d) The deep blue coloration is due to the formation of the complex ion [Fe(CN)6]4- which absorbs light in the red region of the visible spectrum, leaving a blue color.

2. 

a) Burette – used for accurate measurement of liquid volumes, typically in titrations.

b) Beaker – used for holding and heating liquids, mixing, and observing reactions.

c) Erlenmeyer flask – used for mixing and heating liquids, as well as containing and observing reactions. Its sloping sides also make it useful for swirling liquids without spilling.