Ionic Compound Mass (g) T i ( ° C ) Tf (°C) T (°C) q (J) H (J/mol) Calcium chlor
ID: 1056400 • Letter: I
Question
Ionic Compound
Mass (g)
T i (°C )
Tf (°C)
T (°C)
q (J)
H (J/mol)
Calcium chloride
5g
22°C
34°C
+12°C
-251J
Ammonium nitrate
5g
22°C
16°C
-6°C
+125J
Magnesium Carbonate
2g
21°C
21°C
0°C
0
Sodium chloride
5g
21°C
20°C
-1°C
+21J
Cs (water) = 4.18 J/g-°C , Density of water = 1g/mL
Q) Are my calculations for q (J), correct?
Q) Calculate: H (J/mol), for the four ionic compounds?
1. Which (if any) of the reactions were endothermic? Which (if any) of the reactions were exothermic? If no conclusion can be made, write no conclusion. Explain how you used the data you collected to decide if the reactions were endo- or exothermic.
2. If a reaction is exothermic, are the attractive forces between the reactants stronger or weaker than the attractive forces between the products? Explain your answer.
3. Examine the groups of salts whose dissolution was endothermic and those that were exothermic. Discuss the IMF that exists between solute molecules, solvent molecules (water) and between the solute and the solvent. Use IMF to rationalize the heat transfer for each molecule upon dissolution.
Ionic Compound
Mass (g)
T i (°C )
Tf (°C)
T (°C)
q (J)
H (J/mol)
Calcium chloride
5g
22°C
34°C
+12°C
-251J
Ammonium nitrate
5g
22°C
16°C
-6°C
+125J
Magnesium Carbonate
2g
21°C
21°C
0°C
0
Sodium chloride
5g
21°C
20°C
-1°C
+21J
Explanation / Answer
endothermicreaciton there is a temperature drop during the course of reaction. this is happening in ammoniu8m nitrate and sodium chloride. So the dissolutinos are endothermic
the attracitve forces between the reactant is weaker than products. the excess energy li liberted in the form of heat.
3. when the attractive forces between the reactns molecules is stronger than products, heat has to be supplied to brea k the reactants. leading to endothermic reaction.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.