kilojoules released when 80.0g of steam condenses at 100 ∘C and to cool the liquid and freeze it at 0 ∘C
I used the formula for condensation/ evaporation( 80.0g(2260)1kJ/1000J=632.8)
and then i used the formula for heat of fusion(80.0g(334/1)1kJ/1000J=26.72)
then added together (632.8+26.72=659.52kJ)
but the website keeps telling me im wrong. Did I do something wrong in my calculations or did I use the wrong formulas
kilojoules released when 90.0 g of steam condenses at 100 ∘C, cools, and freezes at 0 ∘C
you did not add the heat given off during cooling from 100C to 0C
Well, it seems like you're having a "heat"-sensitive situation with your calculations! Let's break it down and see if we can figure out what went wrong.
First, we need to calculate the heat released when steam condenses at 100 °C. You correctly used the formula for condensation/evaporation, which is Q = m * ΔHvap. For water, ΔHvap is approximately 2260 J/g. So, you multiplied 80.0 g by 2260 and divided by 1000 to convert from J to kJ, which gives you 632.8 kJ. That part looks spot on!
Next, let's calculate the heat released to cool the liquid from 100 °C to 0 °C. However, it seems like you might have used the wrong formula for this step. The formula you used, Q = m * ΔT * C, is actually for calculating the heat absorbed or released during a temperature change, where C is the specific heat capacity. But in this case, we need to calculate the heat released during a phase change.
To freeze the liquid water at 0 °C, we need to use the heat of fusion formula: Q = m * ΔHfus. The heat of fusion, ΔHfus, for water is approximately 334 J/g. We can use the same approach as before to convert it to kJ and multiply it by the mass of 80.0 g. So, the correct calculation for this step is (80.0 g * 334 J/g) / (1000 J/kJ) = 26.72 kJ. Bravo!
Now, to find the total heat released, we simply need to add the heat released during condensation and the heat released during freezing together. So, 632.8 kJ + 26.72 kJ = 659.52 kJ.
Based on your calculations, it seems that you did everything correctly. So, it's possible that there might be a misunderstanding or a typo somewhere else. Remember to double-check all the given data and units. If the website insists you're wrong, maybe it just doesn't appreciate your humorous approach to calculations! Keep up the good work and don't let it rain on your parade!
Your calculations are correct; however, there is a small mistake in one of the formulas you used.
To calculate the heat released during the condensation of steam, you correctly used the formula:
80.0g × 2260 J/g = 180,800 J
To convert this value to kilojoules, you divide by 1000:
180,800 J ÷ 1000 = 180.8 kJ
This is the correct value for the heat released during condensation.
To calculate the heat released during cooling the liquid and freezing it, you used the formula:
80.0g × (334/1) J/g = 26,720 J
Again, converting this value to kilojoules, you divide by 1000:
26,720 J ÷ 1000 = 26.72 kJ
This is also correct.
To get the total heat released, you add these two values:
180.8 kJ + 26.72 kJ = 207.52 kJ
So, the correct answer is 207.52 kJ, not 659.52 kJ as you originally calculated.
Please double-check the calculations on the website or ensure you input the correct answer format for the website you are using.
Your approach for calculating the kilojoules released during the condensation and freezing processes is correct, but there seems to be a small mistake in your calculations. Let me walk you through the correct calculations:
1. Condensation:
To calculate the kilojoules released during the condensation process, you correctly used the formula: 80.0g × 2260 J/g = 180,800 J (note: make sure to use 2260 J/g as the heat of vaporization for water).
To convert this to kilojoules: 180,800 J ÷ 1000 = 180.8 kJ.
2. Freezing:
To calculate the kilojoules released during the freezing process, you need to use the heat of fusion (334 J/g) instead of 334/1. Here's the correct calculation: 80.0g × 334 J/g = 26,720 J.
To convert this to kilojoules: 26,720 J ÷ 1000 = 26.72 kJ.
Now, let's add the two values together: 180.8 kJ + 26.72 kJ = 207.52 kJ.
Therefore, the correct answer is 207.52 kJ, not 659.52 kJ as you mentioned. It's possible that you made a simple arithmetic mistake in your addition. Please double-check your calculations and make sure you use the correct values for the heat of vaporization and heat of fusion.