1.a) If ΔE > 0 then energy is being absorbed by thesystem.
True
False
1.b) If ΔEsystem is positive thenΔEsurrounding must be:
| | negative |
| | none of these |
| | positive |
| | zero 1.c) Consider the following chemical equation and calculate howmuch heat is released when 77.90 grams ofC2H6 reacts.
2 C2H6 + 7 O2 --> 4CO2 + 6H2O                 ΔH= -385 kJ
- answer should read out to one place after the decimal
- do not include units
1.d) A 27.4 g cube of copper initially at 74.6 ºC is submergedinto a cup filled with 121.4 grams of water at 13.6 ºC. Determinethe final temperature of both substances at thermalequilibrium. HINTS:      Specific heatof copper = 0.385 J/g × ºC   Specific heat of water =4.184 J/g × ºC - your answer should contain four significantfigures. 1.e) Calculate the heat (in kJ) associated if 0.0107 kg ofCH4 was used for the reaction:
CH4(g) + 2O2(g)  -->CO2(g) + 2H2O(g)ΔHrxn = -890 kJ
-report answer using three sig figs |
