1. Suppose you use a coffee cup calorimeter to measure the heat released in the

Question

1. Suppose you use a coffee cup calorimeter to measure the heat released in the neutralization reaction between sodium hydroxide and hydrochloric acid. Given the data in the table below, how much heat was released or absorbed in the reaction?

A.-2400 J B.11000 J C.2400 J D.-2200 J

2. Suppose you perform the reaction of magnesium and hydrochloric acid in a different constant pressure calorimeter with a calorimeter constant of 12.75 J/oC. The initial temperature in the calorimeter is 22.5 oC and the final temperature after the reaction is 33.7 oC. What is the value of qcal?

A.287 J B.143 J C.-430 J D.-143 J

mass of empty calorimeter (g) 12.500 g initial temperature in the calorimeter (OC) 22.09C (c 27.5 c final temperature in the calorimeter mass of the calorimeter and its contents after the reaction (g) 110.740 g 24.7 J/9C calorimeter constant

Explanation / Answer

Part 1)

We have,

Heat released = [mass x specific heat x temperature difference + C x temperature difference]

Here, calorimeter constant, C = 24.7 J/oC

Cp = 4.184 J/goC

Therefore, heat released = (110.740 -12.5) x 4.18 x (27.5-22) + (24.7 x 5.5) = 2400 joules

Part 2)

Here, calorimeter constant, C = 12.75 J/oC

Temperature difference = 33.7 - 22.5 = 11.2 oC

qcal = C x temperature difference = 11.2 x12.75 = 143 joules

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.