Question

The following data was collected during the calorimetric run. Graph the data and answer the questions below. (Enter your answers to three significant figures.) Table 1: Time and Temperature

Time (s)	Temperature (°C)
−60.	23.7
−30.	23.7
30.	9.7
60.	10.5
90.	10.9
120.	11.3
150.	11.5
180.	11.7
210.	11.9
240.	12.0
270.	12.2
300.	12.3
330.	12.4
360.	12.5
390.	12.6
420.	12.6
450.	12.7
480.	12.8
510.	12.9
540.	12.9
570.	13.0
600.	13.0

a) What is the initial temperature based on the calorimetric run? b) What is the final temperature based on the calorimetric run? c) If the total mass of the solution was 35.3 g and the heat capacity of the solution is the same as water (4.1801 J/g·°C), what is the value of q for the run? d) What is the value of q for the reaction? e)Is the reaction endothermic or exothermic?

Answer 1

a) The initial temperature based on the calorimetric run is 23.7°C

b) The final temperature based on the calorimetric run is 13.0°C

c)  The total mass of the solution was m = 35.3 g and Molar mass of water (M) = 18 g/mol

the heat capacity of the solution is the same as water (C = 4.1801 J/g·°C) and Q = (23.7-13)°C = 10.7 °C is raise in temperature

q = C* Q*(M/m) = 4.1801 J/g·°C * (10.7 °C )* (18g/mol/35.3 g) = 44.7270 * 0.5099 J/g.mol = 22.8069 J/g.mol

the value of q for the run =  22.8069 J/g.mol

d) The value of q for the reaction =  -22.8069 J/g.mol

e) the reaction is Exothermic as heat is released