Q: consider the dissolution of CaCl 2: CaCl 2 (s) -> Ca 2+ (aq)+2Cl - (aq) H: -8
ID: 681992 • Letter: Q
Question
Q: consider the dissolution of CaCl2:CaCl2 (s) -> Ca 2+ (aq)+2Cl- (aq) H: -81.5kj An 11.0 g sample of CaCl2 is dissolved in 125 g ofwater with both subsances at 25 degree C. Calculate the finaltemperature of the solution assuming no heat is lost to thesurrounding and assuming the solution has a specific heat capacityof 4.18J/degrees C x g. Q: consider the dissolution of CaCl2:
CaCl2 (s) -> Ca 2+ (aq)+2Cl- (aq) H: -81.5kj An 11.0 g sample of CaCl2 is dissolved in 125 g ofwater with both subsances at 25 degree C. Calculate the finaltemperature of the solution assuming no heat is lost to thesurrounding and assuming the solution has a specific heat capacityof 4.18J/degrees C x g.
Explanation / Answer
First figure the number of moles youhave reacted. mass/molar mass =11.0/110.98 moles = .0991 moles of CaCl2 1 mole of CaCl2 will produce -81.5kj ofheat In our case we only have .0991 moles so .0991 * 81.5 = 8.07665kJ so .0991 moles will yield 8076.65 J of heat. mass of water = 125 g mass of CaCl2 = 11.0 g initial temp = 25oC q = m*c*t q = 8076.65 J c = 4.18 J/C *g t = (tf- ti) = (tf - 25 C) mass of the entire solution = mass of water + mass ofCaCl2 = 125+11 = 136 g 8076.65 = 4.18 * 136 * (tf -25) 14.21 = (tf-25) tf= 39.2 C
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.