All categories

3 years ago

What is the energy change if 84.0 g of calcium oxide (CaO) reacts with excess water in the following reaction?

1 answer:

6 0

The energy change if 84.0 g of CaO react with excess water is 98KJ of heat is released.

calculation
heat = number of moles x delta H

delta H = - 65.2 Kj/mol

first find the number of moles of CaO reacted

moles = mass/molar mass
the molar mass of CaO = 40 + 16= 56 g/mol
mass = 84 g
moles therefore = 84 g/56 g/mol =1.5 moles

Heat is therefore = 1.5 moles x -65.2 = - 97.8 Kj = -98 Kj

since sign is negative the energy is released

You might be interested in

Which choice lists the correct order of the coefficients of each substance in the following neutralization reaction when the equ

Gnoma [55]

The third one you have listed

4 0

3 years ago

The penguin has a ___ body that helps it to move quickly in water.

Lerok [7]

The penguin has a sleek body that helps it to move quickly in water.

7 0

3 years ago

Read 2 more answers

What is the temperature of a water body containing a 90% saturation and 11.5 ppm of dissolved oxygen?

ozzi

Using the chart that has been provided, we may determine water temperature. We do this by drawing a straight line form the bottom scale which has the ppm of oxygen dissolved to the middle scale which has the percentage saturation.

The line starts from 11.5 ppm on the bottom scale and goes to 90% on the middle scale. Next, we continue this line, without changing its slope, to the third scale showing temperature. We see that it crosses the temperature scale at 4°C.

The temperature of the water is 4 °C.

6 0

3 years ago

A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is

Anuta_ua [19.1K]

The maximum safe operating temperature for this reaction is equal to 895°C.

<u>Given the following data:</u>

Width of cylinder = 22 cm.

Height, h = 26.4 cm.

Maximum safe pressure = 6.30mpa.

Mass = 0.537 kg.

<u>Scientific data:</u>

Ideal gas constant, R = 8.314 L-kPa/Kmol.

Molar mass of of dinitrogen monoxide ( $N_2F_2$ ) gas = 66 g/mol.

Radius, r = $\frac{width}{2} =\frac{22}{2} =11\;cm$

<h3>How to calculate the maximum safe operating temperature.</h3>

First of all, we would determine the volume of the stainless-steel cylinder by using this formula:

$V=\pi r^2 h\\\\V = 3.142 \times 11^2 \times 26.4\\\\$

Volume, V = 10,036.81 $cm^3$ .

In liters, we have:

Volume, V = 10.04 Liters.

Next, we would determine the number of moles of dinitrogen monoxide ( $N_2F_2$ ) gas:

$Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {537}{66}$

Number of moles = 8.136 moles.

Now, we can solve for the maximum safe operating temperature by applying the ideal gas equation:

$PV=nRT\\\\T=\frac{PV}{nR} \\\\T=\frac{6.30 \times 10^3 \times 10.04}{8.136 \times 8.314}\\\\T=\frac{60541.2}{67.6427}$

T = 895.02 ≈ 895°C.

Read more on temperature here: brainly.com/question/24769208

5 0

2 years ago

What information do the coefficients of a balanced equation give about the reactants

Nana76 [90]

The information that the coefficients of a balanced equation give about the reactants are to tell how many moles of reactants are needed and how many moles of product can be produced.

4 0

3 years ago