WC 1M Post Challenge - You Ready?!

Pete The Penguin

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Q-100g ice at 0?C is mixed with 10g steam at 100?C. Find the final temperature and composition.
How to solve? :confused:

Use the following equation to determine the amount of energy required to melt the ice.
Q = mass * Hf = 3.36 * 10^5 J

Use the following equation to determine the amount of energy required to increase the temperature of water from 0 to 100.

Q = mass * Specific heat * ∆T
Specific heat = 4186 J/(kg * ˚C)
Q = 1 * 4186 * 100 = 418,600 J
Total energy required = 3.36 * 10^5 + 418,600 = 7.546 * 10^5 J

This is the amount of energy that is required to melt the ice and increase the temperature of the water to 100˚C. Let?s use this number in the following equation to determine the amount of steam that it will condense.

Q = mass * H vap = 2.26 * 10^6 J
7.546 * 10^5 = mass * 2.26 * 10^6
Mass = 7.546 * 10^5 ? 2.26 * 10^6 = 0.333893805 kg

This is approximately 0.334 kg. This means all of the steam didn't condense. To determine the mass of steam that didn't condense, subtract this number from 1kg. The mass is approximately 0.666 kg.
 

Lumia Lumia

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re: WC 100K Post Challenge - You Ready?!

Use the following equation to determine the amount of energy required to melt the ice.
Q = mass * Hf = 3.36 * 10^5 J

Use the following equation to determine the amount of energy required to increase the temperature of water from 0 to 100.

Q = mass * Specific heat * ∆T
Specific heat = 4186 J/(kg * ˚C)
Q = 1 * 4186 * 100 = 418,600 J
Total energy required = 3.36 * 10^5 + 418,600 = 7.546 * 10^5 J

This is the amount of energy that is required to melt the ice and increase the temperature of the water to 100˚C. Let?s use this number in the following equation to determine the amount of steam that it will condense.

Q = mass * H vap = 2.26 * 10^6 J
7.546 * 10^5 = mass * 2.26 * 10^6
Mass = 7.546 * 10^5 ? 2.26 * 10^6 = 0.333893805 kg

This is approximately 0.334 kg. This means all of the steam didn't condense. To determine the mass of steam that didn't condense, subtract this number from 1kg. The mass is approximately 0.666 kg.


Er, in the answer it is given that the resulting temperature is 0?C, and the ice and water remaining in the mixture is 20g and 90g respectively....i didn't understand how?
 

psoham777

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re: WC 100K Post Challenge - You Ready?!

Antarctica is a "polar" region, there is no precipitation, it has no lakes or rivers and is in fact the driest continent. Average temperatures in the Antarctic interior get down to -70 degrees Celsius during the winter months and -35 degrees Celsius in the warmer months. The coastal temperatures are much warmer with a range of -15 to -32 Celsius in Winter and -5 to +5 Celsius in Summer. The interior of Antarctica is considered the world's driest desert because the extreme cold freezes water vapour out of the air. Annual snowfall on the polar plateau is equivalent to less than 5 cm of rain. Antarctica has some of the strongest winds on earth, with some winds reaching 320 kph.

So, no snowflakes, see.


& you get this information from your friends in Antarctica?
 

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