The molar heat of vaporization of water is 42 kJ/mol. How much energy is released by the condensation of 3.0 g of water?

So for water there will just be one mol.
I think this is how you do it, but it doesn't match the answer in the worksheet.

q=mc delta t
But we're not given a temperature?
q= (3.0g)(4.18 J/g x degrees celsius)
q= 12.54

And we know that + or - q= Hrxn

And that Hrxn=Hvap
???
I think I'm not even on the right track. Any help would be really appreciated. Thank you!!!

You're right. You started out wrong.

q = mols H2O x heat condensation
mols H2O = grams/molar mass = 3/18 = ?
q = (3/18) x 42,000 J = ? J released.

Well, when it comes to water, it can be quite the comedian. So, let's see if we can make sense of this together!

To find the energy released by the condensation of 3.0 g of water, we need to use the molar heat of vaporization, which is given as 42 kJ/mol. However, we first need to find the number of moles of water in 3.0 g.

Now, the molar mass of water (H2O) is approximately 18.0 g/mol. So, to find the number of moles, we can use the equation:

moles = mass / molar mass

Substituting the given values:

moles = 3.0 g / 18.0 g/mol
moles ≈ 0.167 mol

Now that we know the number of moles, we can find the energy released by using the molar heat of vaporization. The equation for calculating the heat (q) is given by:

q = n × ΔHvap

Where:
q is the energy released (in joules),
n is the number of moles, and
ΔHvap is the molar heat of vaporization (in joules/mol).

Substituting the given values:

q = 0.167 mol × 42 kJ/mol
q ≈ 7.014 kJ

So, it appears that the energy released by the condensation of 3.0 g of water is approximately 7.014 kJ. Now, remember to always check the units and make sure to convert them if needed, as they can sometimes be quite the jokester!

I hope this helps, and remember, when in doubt, water you waiting for? Dive in and let the humor flow!

To calculate the energy released by the condensation of water, you need to use the molar heat of vaporization.

First, calculate the moles of water being condensed:
moles = mass / molar mass
molar mass of water (H₂O) = 18.015 g/mol
moles = 3.0 g / 18.015 g/mol ≈ 0.1665 mol

Next, use this value to calculate the energy released:
Energy released = moles × molar heat of vaporization
Energy released = 0.1665 mol × 42 kJ/mol = 7.998 kJ

The energy released by the condensation of 3.0 g of water is approximately 7.998 kJ.

To calculate the amount of energy released by the condensation of 3.0 g of water, you need to use the molar heat of vaporization. Here's how you can approach it:

1. Convert the mass of water (3.0 g) to moles. To do this, you need to know the molar mass of water, which is approximately 18 g/mol. Divide the mass by the molar mass:

moles = mass / molar mass
moles = 3.0 g / 18 g/mol
moles ≈ 0.167 mol

2. Now that you have the number of moles, you can use the molar heat of vaporization (Hvap) to determine the amount of energy released. The molar heat of vaporization for water is given as 42 kJ/mol.

energy released = moles × Hvap
energy released = 0.167 mol × 42 kJ/mol
energy released ≈ 7.014 kJ

Therefore, approximately 7.014 kJ of energy is released by the condensation of 3.0 g of water.

It seems like you were trying to use the heat capacity equation (q = mc∆T), which is used to calculate the amount of heat absorbed or released during a temperature change. However, in this case, the temperature doesn't change during the condensation process. Instead, you need to use the molar heat of vaporization to calculate the energy released.