Name KEY
Period ……
Regents Chemistry
Converting between the Celsius and Kelvin Scales
There are two commonly used scales for measuring temperature in science. One you may already be familiar
with – the Celsius scale. The other scale used for measuring temperature in science is the Kelvin scale. One
Kelvin degree is EQUAL TO one degree Celsius, but the two scales start with different numbers.
BOTH scales start at ABSOLUTE ZERO, which is the (theoretical) temperature at which particles of matter
completely stop moving. Absolute zero is the lowest temperature possible.
Absolute zero in Kelvins is 0 K.
Absolute zero in degrees Celsius is –273 °C.
At what temperature does water freeze on the Celsius scale?
At what temperature does water boil on the Celsius scale?
0°C
the Kelvin scale? 273 K
100°C
the Kelvin scale? 373 K
Q: What is the rule for converting from °C to Kelvins?
Add 273 to the Celsius temperature to get Kelvins
Q: What is the rule for converting from Kelvins to °C?
Subtract 273 from the Kelvin temperature to get to Celsius
1. Convert the following Celsius temperatures into Kelvins (SHOW YOUR WORK):
a.
b.
c.
d.
e.
f.
g.
5 °C + 273 = 278 K
78 °C + 273 = 351 K
100 °C + 273 = 373 K
250 °C + 273 = 523 K
273 °C + 273 = 546 K
–55 °C + 273 = 218 K
373 °C + 273 = 646 K
h.
i.
j.
k.
l.
m.
400 °C + 273 = 673 K
–10 °C + 273 = 263 K
–157 °C + 273 = 116 K
–273 °C + 273 = 0 K (Absolute Zero!)
37 °C + 273 = 310 K
25 °C + 273 = 298 K
2. Convert the following Kelvin temperatures into degrees Celsius (°C) (SHOW YOUR WORK):
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
5 K – 273 = –268 ºC
78 K – 273 = –195 ºC
100 K – 273 = –173 ºC
250 K – 273 = –23 ºC
273 K – 273 = 0 ºC (the temperature at which water freezes/melts)
550 K – 273 = 277 ºC
373 K – 273 = 100 ºC (the temperature at which water boils/condenses)
400 K – 273 = 127 ºC
10 K – 273 = –263 ºC
157 K – 273 = –116 ºC
200 K – 273 = –73 ºC
37 K – 273 = –236 ºC
25 K – 273 = –248 ºC
Is it possible to have a negative Kelvin temperature? Explain.
No, it is not possible to have a negative Kelvin temperature because 0 Kelvin is the lowest possible
temperature (absolute zero).