Question

Question 4

2 pts
Note: For this question, parts B, C, and D are related. In other words, the answer to
Part B is needed to answer question C and the answer to C is needed for D.
Calculations in this question are similar to those completed for your Lab Report.
Question: When 5.12 g of NaOH were dissolved in 51.55 g of water in a calorimeter
at 24.5 °C, the temperature of the solution increased to 49.8 °C.
Part B: Calculate the heat absorbed by the water, QH20 in J. Do not include units in
your answer.
Question 5
2 pts
Note: For this question, parts B, C, and D are related. In other words, the answer to
Part B is needed to answer question C and the answer to C is needed for D.
Question: When 5.12 g of NaOH were dissolved in 51.55 g of water in a calorimeter
at 24.5 °C, the temperature of the solution increased to 49.8 °C.
Part C: Determine the heat given off by the dissolution of NaOH, an in J (recall an
-QH20) If this quantity is negative, ensure you include a "-" in your answer. Do not
include units when typing your answer.

Answer 1

Part B: To calculate the heat absorbed by the water, we can use the formula:

Q = m x C x ∆T

where Q is the heat absorbed by the water, m is the mass of the water, C is the specific heat capacity of water (4.184 J/g°C), and ∆T is the change in temperature.

First, we need to calculate the mass of the water. We know that 51.55 g of water were used, so:

m = 51.55 g

Next, we can calculate ∆T:

∆T = 49.8 °C - 24.5 °C = 25.3 °C

Now, we can substitute these values into the formula to get Q:

Q = m x C x ∆T = 51.55 g x 4.184 J/g°C x 25.3°C = 5472.13 J

Therefore, the heat absorbed by the water, QH2O, is 5472.13 J.

Part C: To determine the heat given off by the dissolution of NaOH, we can simply use the fact that energy is conserved in the process. This means that the heat absorbed by the water (QH2O) is equal in magnitude but opposite in sign to the heat given off by the dissolution of NaOH (QNaOH):

QNaOH = -QH2O

We already calculated QH2O in Part B, so:

QNaOH = -5472.13 J

Therefore, the heat given off by the dissolution of NaOH, QNaOH, is -5472.13 J, which is negative because it represents a release of energy (exothermic process).

Step-by-step explanation:

Part B: To calculate the heat absorbed by the water, we can use the formula:

Q = m x C x ∆T

where Q is the heat absorbed by the water, m is the mass of the water, C is the specific heat capacity of water (4.184 J/g°C), and ∆T is the change in temperature.

First, we need to calculate the mass of the water. We know that 51.55 g of water were used, so:

m = 51.55 g

Next, we can calculate ∆T:

∆T = 49.8 °C - 24.5 °C = 25.3 °C

Now, we can substitute these values into the formula to get Q:

Q = m x C x ∆T = 51.55 g x 4.184 J/g°C x 25.3°C = 5472.13 J

Therefore, the heat absorbed by the water, QH2O, is 5472.13 J.

Part C: To determine the heat given off by the dissolution of NaOH, we can simply use the fact that energy is conserved in the process. This means that the heat absorbed by the water (QH2O) is equal in magnitude but opposite in sign to the heat given off by the dissolution of NaOH (QNaOH):

QNaOH = -QH2O

We already calculated QH2O in Part B, so:

QNaOH = -5472.13 J

Therefore, the heat given off by the dissolution of NaOH, QNaOH, is -5472.13 J, which is negative because it represents a release of energy (exothermic process).