Question
How do I solve questions 1-6?.
I don't understand this lab
A. EQUILIBRIUM of SOLID AMMONIUM CHLORIDE with AMMONIUM CHLORIDE in AQUEOUS SOLUTION NH,CI (S) + Ho NH (aq)C (aq) + CI (aq) ammonium chloride Exothermie reachon Place 10 drops of saturated NHsCI solution into, clean dry test tube. Add 10 drops of concentrated HCI solution and shake. If you do not see any change, add a few more drops of conc. HCI. . e Note: HCI solution contains H and Cl- ions. Use a test tube holder and place the test tube in the boiling water bath, shake and observe any change after a few minutes. Use a spatula and place a few crystals of solid ammonium chloride at the bottom of a small, clean odry test tube. Touch the bottom to qualitatively note the warmth or coolness. (do not let the warmth of tour hand change the test tube temperature). Now add about 10 drops of DI water quickly to the test tube and feel the tube again to see if there is any temperature change. QUESTIONS What did you observe when you added the concentrated HCl solution to the saturated solution of ammonium chloride? solution turned whte and started 1. olid The test tube became warm rn 2. Interpret the observation in question 1 in terms of the equation given above and Le Chatelier's principle. 3. What did you observe when you placed the test tube (after the addition of concentrated HCI to it) in the boiling water bath? Based on your observations in question 3,which of the above reactions (forward or reverse) in the equilibrium written (solid ammonium chloride in equilibrium with ammonium ions an chloride ions) above is endothermic and which is exothermic? Explain
Explanation / Answer
1) Precipitate formation can be observed, NH4Cl tends to form ppt when HCl is added to saturated solution
of NH4Cl
2) NH4Cl <------> NH4+ + Cl-
When HCl is added the concentration of Cl- will increase and the equilibrium tends to shift left
because there is change in concentration of Cl- in the right. According to the Le Chatlier's
principle the shift occurs opposite in direection to Change or stress.
3) The precipitate will dissolve, NH4Cl + heat ------> NH4+ + Cl-
4) NH4Cl + heat ------> NH4+ + Cl- will move in forward direction
NH4Cl (s) + H2O -------> NH4+ (aq) + Cl- (aq) is an endothermic reaction
