Question

1.2 g of cesium hydroxide is dissolved in 100.0 g of water initially at 25.0oC. When all of the cesium chloride is dissolved, the temperature rises to 26.4oC.

What is the heat of reaction qrxn after the compound is completely dissolved? Use the formula qrxn =-(4.184 x msolution x ΔT) where msolution is the sum of the masses of the cesium hydroxide and the water, and ΔT equals the final temperature minus the initial temperature.


Type in your answer to the correct number of significant figures, but do NOT include the unit J (Joules) in your answer. Use standard notation, and not scientific notation. For example only, type in 4980 and not 4.980 x 103.

Answer 1

-588.1168

Step-by-step explanation:

To calculate the heat of reaction (qrxn), we need to use the formula:

qrxn = -(4.184 x msolution x ΔT)

Given:

Initial temperature (T1) = 25.0°C

Final temperature (T2) = 26.4°C

Mass of cesium hydroxide (m1) = 1.2 g

Mass of water (m2) = 100.0 g

First, let's calculate the sum of the masses of cesium hydroxide and water (msolution):

msolution = m1 + m2

msolution = 1.2 g + 100.0 g

msolution = 101.2 g

Next, let's calculate the change in temperature (ΔT):

ΔT = T2 - T1

ΔT = 26.4°C - 25.0°C

ΔT = 1.4°C

Now, we can substitute the values into the formula to calculate the heat of reaction (qrxn):

qrxn = -(4.184 x msolution x ΔT)

qrxn = -(4.184 x 101.2 g x 1.4°C)

qrxn = -588.1168 J(joule may not be included)

Therefore, the heat of reaction (qrxn) after the compound is completely dissolved is approximately -588.12 J. Note that the negative sign indicates an exothermic reaction, meaning heat is released.