DO NOW: (on the front of your WS) Define each of the variables below AND list all possible units!   Units: q = _______________ _________ m = _______________ _________ c = _______________ _________ ∆T = _______________ _________

q=mcΔT q= m= c= ΔT= heat (J or cal) mass (grams) specific heat g˚C cal g˚C J specific heat or change in temperature (˚C) (Tfinal-Tinitial)

Unit: Thermochemistry Notes Unit: Thermochemistry q=mcΔT Day 2

After today you will be able to… Explain specific heat (c) and use the specific heat equation: q=mcΔT

q= (257g) (2.4 J/g˚C) (49.1˚C) q= 30,285 J = 3.0 x 10⁴ J Example: How much heat (in Joules) is needed to raise the temperature of 257 g of ethanol (c = 2.4 J/g˚C) by 49.1˚C. q= ? J m= 257 g c= 2.4 J/g˚C ΔT= 49.1˚C q= (257g) (2.4 J/g˚C) (49.1˚C) q= 30,285 J = 3.0 x 10⁴ J

? J = (1370 g) (4.18 J/g˚C) (68.2˚C) q = 391 kJ Example: How many kilojoules of heat are required to heat 1.37 kg of water from 21.3°C to 89.5°C? q= ? kJ 1000 g m= 1.37 kg x = 1370 g 1 kg c= 4.18 J/g˚C ΔT= 89.5-21.3= 68.2˚C ? J = (1370 g) (4.18 J/g˚C) (68.2˚C) 1 kJ q = 390,554 J x 1000 J q = 391 kJ

Questions? Complete WS!

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