Question

5. (20 pts) Consider the following reaction OF2(g) + H2O(g) ---> 2 HF(g) + O2(g) AH.(kJ/mole) -318 kJ/mole (a) Using this information along with data in the appendix of your textbook, calculate AH;(OF,(8)) in kJ/mole at 25°C. (b) If 15.0 g of OF2(g) and 10.0 g of H2Og) react, how much heat, expressed in kJ is released? Hint: First calculate the limiting reagent. 6.(20 pts) Consider two Styrofoam coffee cups. If cup #1 contains 102.0 mL of water at 81.8°C and cup #2 contains 74.6 mL of water at 13.5°C, what is the final temperature, in °C, when the contents of cup #1 are poured into cup #2? Ignore the heat capacity of the cup. Assume that the density of water is 1.00 g/mL.

Answer 1

Guen chemicl seaction is HERt O4 OF H01&) AH 318KT Data arailable Heat ot bonelin lAH) in kmal Substan Ce O2 Ca) H20 (8) HE La O - 241 8 -271.6

=2x (AE.१) + AHi(DF)t A (40.3) 2x-(2716)+o-4H0)294)2 318 271-6 X2) + 318 + 241 8 वा १.१० Given balanced chemal ah OF ) H0 (9) 2HF ) 0, ) AH3127 Mot iven ma 153 = 5 totar wars= 547 18 No o5 no les 4 0.28 Here Ofz is mole is len than melo ap of waterlu But n seacim OF o shenld Le limibng reagent tecaure its imitiny agente o

Mele ot Ofz aftes seathon AHT -218 11S 4 heat seleasd-19875k Let heat capaity of waters when minest too ligidexchange theat occuss taom high temp to Lewer temp tutil both lunids attan tu sause tembesatase .hest lest =hest ा, myATE mi AT Let inal teap 02x -T = 74.6AT-13.5) denoty -7l diniy wlume mas

f02X 81.8+ 74.6X1B-5 T = 102+74.6 T 53C final temp 53e Aus