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The boiling point of a substance is a temperature of 500 degrees Fahrenheit.
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Express this as a kelvin temperature.
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Okay, so in this case, weβve got a substance which has a boiling point of 500 degrees Fahrenheit.
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What weβre asked to do is to express this in kelvin.
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We can do this in two ways.
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Firstly, we can convert the temperature in degrees Fahrenheit to a temperature in degrees Celsius.
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To do this, we can use the conversion formula between Fahrenheit and Celsius.
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Then, once we have a temperature in degrees Celsius, we can convert it to kelvin.
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The second method is to convert directly from degrees Fahrenheit to kelvin by combining the conversion formulas: the conversion formula from degrees Fahrenheit to degrees Celsius and the one from degrees Celsius to kelvin.
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So the first conversion formula we need to know, π sub πΆ β the temperature in degrees Celsius β is equal to five-ninths multiplied by π sub πΉ β the temperature in Fahrenheit β minus 32.
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This is a conversion formula between degrees Fahrenheit and degrees Celsius.
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So letβs use this conversion formula and apply it to our first method.
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Weβve already been given π sub πΉ β thatβs 500 degrees Fahrenheit.
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So we can plug that into our equation.
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Therefore, we find that π sub πΆ β the temperature in degrees Celsius β is equal to five-ninths multiplied by 500 minus 32, where 500 is the temperature in degrees Fahrenheit.
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We can evaluate this to find that π sub πΆ is equal to 260 degrees Celsius.
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From here on, we need our second conversion formula: π sub πΎ β the temperature in kelvin β is equal to π sub πΆ β the temperature in degrees Celsius β plus 273.
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We can substitute π sub πΆ with 260.
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So weβve got π sub πΎ is equal to 260 plus 273.
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This gives us our final answer that π sub πΎ β the temperature in kelvin β is 533 kelvin.
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But remember we said that we can do this another way by combining the two conversion formulas that weβve written down on the right.
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The second conversion formula says that π sub πΎ is equal to π sub πΆ plus 273.
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But we already know that π sub πΆ is all of this on the right-hand side.
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So we can substitute that in.
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We get that π sub πΎ is equal to five-ninths multiplied by π sub πΉ minus 32 and then we add 273 to it.
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What weβve done here is to find a direct conversion between the temperature in degrees Fahrenheit and the temperature in kelvin.
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This way we donβt need to go via degrees Celsius.
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So essentially, the calculation is exactly the same.
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But whatβs changed is that we no longer need an intermediate temperature in degrees Celsius.
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Weβve combined the two formulas together rather than applying the formulas one by one.
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And so we find that π sub πΎ is equal to five-ninths multiplied by 500 minus 32 plus 273.
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And of course, weβve substituted 500 in for π sub πΉ.
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Evaluating this, we once again find that our temperature in kelvin is 533 kelvin.