CHELLZL Final Exam Fall 2017 Name dissolved in 50 mL of before the solid glucose
ID: 694886 • Letter: C
Question
CHELLZL Final Exam Fall 2017 Name dissolved in 50 mL of before the solid glucose was added was 22 60°C a water The the temperature of the resulting solution was 21.27°C that th d after the 2 In a coffee cup calorimeter, 5.00 g of glucose CsHiz0s was temperature of the water addibion, t the resulting solution is the same as that of pure water (1.00 g/mL) and that the or he solution is also the same as that of pure water (4.184 Jig K). Molasat capacity 80.0 glmol and Assume lar mas s of glucose is a) (1 point) What is the equation for this process of dissolution of g ucose? () (2 points) How much heat (q) was released or absorbed by the solution? 2points) What is the enthalpy change in kJ/mol for this process?Explanation / Answer
a-
solid glucose goes in to aqueous solution:
C6H12O6(s) = C6H12O6(aq)
b-
heat
Q = m*C*(Tf-TI)
Q =50*4.184*(21.27-22.60 )
Q = -278.236 J
this is being absorbed, since T decreases
c
enthalpy change:
mol of glucose = mass/MW = 5/180 = 0.027777
HRNX = -Q/n = --278.236 /0.027777
HRXN = 10016.77 J/mol
HGRXN = 10.02 kJ/mol