A reaction between HCl and NaOH is being studied in a styrofoam coffee cup
with a lid and the heat given off is measured by means of a thermometer
immersed in the reaction mixture. Enter the correct thermochemistry term
to describe the item listed.
1. The type of thermochemical process
2. The ...
Question 1
Not yet graded / 10 pts
Click this link to access the Periodic Table. This may be helpful throughout the exam. A reaction between HCl and NaOH is being studied in a styrofoam coffee cup with a lid and the heat given off is measured by means of a thermometer immersed in the reaction mixture. Enter the correct thermochemistry term to describe the item listed. 1. The type of thermochemical process
2. The calorimeter and mixture of HCl + NaOH
Your Answer:
1. The type of thermochemical process is an acid base reaction or neutralization reaction where heat is given off called a exothermic reaction. 2. The calorimeter and mixture of HCl + NaOH would be described as enthalpy or the total energy of the system. 1. Heat given off = Exothermic process
2. With lid = closed system Question 2
Not yet graded / 10 pts
Click this link to access the Periodic Table. This may be helpful throughout the exam. 1. Show the calculation of the final temperature of the mixture when a 31.6
gram sample of water at 92.3 oC is added to a 40.5 gram sample of water at 25.1oC in a coffee cup calorimeter.
c (water) = 4.184 J/g oC 2. Show the calculation of the energy involved in melting 85 grams of ice at 0oC if the Heat of Fusion for water is 0.334 kJ/g.
Your Answer:This study source was downloaded by 100000812546443 from CourseHero.com on 06-06-2023 04:09:21 GMT -05:00
https://www.coursehero.com/file/60489620/module-3-exam-with-answersdocx/ 1.
- (mwarm H2o x Cwarm H2O x ∆twarm H2O) = (mcool H2O x ccool H2O x ∆tcool H2O) - [31.6 g x 4.184 J/g°C x (T mix - 92.3°C)] = [40.5g x 4.184 J/g°C x (T mix - 25.1°C)]
- [132.2144 J/°C x (T mix - 92.3°C)] = [169.452 J/°C x (T mix - 25.1°C)]
-132.2144Tmix + 12,203.3891 = 169.452T mix - 4,253.2452
16,456.6343 = 301.6664T mix
Tmix = 54.55°C
2. qI↔s = m x ∆Hfusion qI↔s = 85 g x 0.334 kJ/g qI↔s = 28.39 kJ and because heat is added + 28.39 kJ
1. - (mwarn H2O x cwarn H2O x ∆twarn H2O) = (mcool H2O x ccool H2O x ∆tcool H2O) - [31.6 g x 4.184 J/g oC x (Tmix - 92.3oC)] = [(40.5 g x 4.184 J/g oC x (Tmix - 25.1oC)] - [132.2144 J/oC x (Tmix - 92.3oC)] = [(169.452 J/ oC x (Tmix - 25.1oC)] Tmix = 54.6oC 2. ql↔s = m x ∆Hfusion = 85 g x 0.334 kJ/g = 28.39 kJ (since heat is added) = +
28.39 kJ Question 3
Not yet graded / 10 pts
Click this link to access the Periodic Table. This may be helpful throughout the exam. Show the calculation of the amount of heat involved if 18.3 g of S is reacted with excess O2 to yield sulfur trioxide by the following reaction equation. Report your answer to 4 significant figures. 2 S (s) + 3 O2 (g) → 2 SO3 (g) ΔH = - 792 kJ
Your Answer:This study source was downloaded by 100000812546443 from CourseHero.com on 06-06-2023 04:09:21 GMT -05:00
https://www.coursehero.com/file/60489620/module-3-exam-with-answersdocx/
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