Answer to Question #203796 in General Chemistry for lea

Question

Which of these changes are endothermic? Which are exothermic? (You must know the names for each of the phase changes.) please explain

a) Melting of ice

b) CH4 (g) + 2 O2 (g) --> CO2 (g) + 2 H2O (g) + 882 kJ

c) Deposition of iodine

d) NH4Cl (s) --> NH4Cl (aq) ΔH° = + 14.7 kJ/mol

e) Calcium oxide solid dissolving in water causes a temperature increase

Which of these changes are endothermic? Which are exothermic? (You must know the names for each of the phase changes.)

a) Water accumulating on grass early in the morning

b) Solidification of liquid magma

c) 3NO2 + H2O --> 2HNO3 + NO ∆H = - 138 kJ

d) 6CO2 + 6H2O + 2803 kJ --> C6H12O6 + 6O2

e) Sugar crystalizing in a saturated solution.

Answer 1

Exothermic

a). Melting of ice

b). CH4 (g) + 2 O2 (g) --> CO2 (g) + 2 H2O (g) + 882 kJ

c). Calcium oxide solid dissolving in water causes a temperature increase

Endothermic

a). 6CO2 + 6H2O + 2803 kJ --> C6H12O6 + 6O2

b). Deposition of iodine

c). NH4Cl (s) --> NH4Cl (aq) ΔH° = + 14.7 kJ/mol