Copper(II) nitrate decomposes on heating. The reaction is endothermic. 2Cu(NO 3 ) 2 (s) 2CuO(s) +
Question:
Copper(II) nitrate decomposes on heating. The reaction is endothermic.
2Cu(NO3)2(s) → 2CuO(s) + 4NO2(g) + O2(g)
a. Draw an enthalpy level diagram (reaction profile diagram) for this reaction.
b. Draw an enthalpy cycle diagram to calculate the standard enthalpy change for this reaction, using enthalpy changes of formation.
c. Calculate the enthalpy change for this reaction using the following enthalpy changes of formation.
ΔHQf [Cu(NO3)2(s)] = –302.9 kJ mol–1
ΔHQf [CuO(s)] = –157.3 kJ mol–1
ΔHQf[NO2(g)] = +33.2 kJ mol–1
d. Copper(II) sulfate is soluble in water. A student dissolved 25.0 g of copper(II) sulfate in 100 cm3 of water in a polystyrene beaker stirring all the time. The temperature of the water fell by 2.9°C.
i. Calculate the enthalpy change of solution of copper(II) sulfate. (specific heat capacity of water = 4.18 J g–1°C–1; relative molecular mass of copper(II) sulfate = 249.7 g mol–1)
ii. Suggest one source of error in this experiment and explain how the error affects the results.
Step by Step Answer:
Cambridge International AS And A Level Chemistry Coursebook
ISBN: 9781316637739
2nd Edition
Authors: Lawrie Ryan, Roger Norris