Ellington - Specific Heat Math

Ellington - Specific Heat Math

What are we doing today?

In the warm up question, you thought about a pot of water absorbing energy from the stove. We are going to try to calculate EXACTLY how much energy it absorbed.

First thing we need to know is Specific Heat

• Physical Property of a substance

• Ex: Specific heat of water = 4.18 J/°C g

• If we KNOW the specific heat, we can use it to calcuate the total energy transfered in a system 

Next week need the full equation

q= heat

m = mass

C = Specific Heat

ΔT = Change in Temperature

Multiple Choice

What units are used to measure mass?

• grams

• Joules

• °C

• ml

Multiple Choice

What units are used to measure Temperature?

• grams

• ml

• Joules

• °C

Multiple Choice

I just said this today: What units are used to measure HEAT?

• grams

• Joules

• ml

• °C

Multiple Choice

ΔT = Change in Temperature. How would you calculate the change in temperature?

• Final temperature minus starting temperature

• Starting temperature minus final temperature

Multiple Choice

250g of water (specific heat of 4.184 J/g^oC) is heated from 20^oC to 46^oC.

What is the change in temperature?

• 26^oC

• -26^oC

• 250g

• 66^oC

Multiple Choice

250g of water (specific heat of 4.18 J/g^oC) is heated from 20^oC to 46^oC.

How would you calculate the total heat absorbed by the water?

• 250g x 4.18J/g^oC x 26^oC

• 46^oC - 20^oC

• 250 + 4.18 + 26

Multiple Choice

SOLVE IT: 250g of water (specific heat of 4.18 J/g^oC) is heated from 20^oC to 46^oC.

How much heat did the water absorb?

• 27,170 J

• 20,900 J

• 48,070 J

More practice coming your way!

Do you have this equation written down???

Open Ended

Calculate the amount of heat needed to raise the temperature of 15g of copper from 25^oC to 60^oC if copper has a specific heat of 0.386 J/g^oC

Open Ended

How much energy is required to raise the temperature of 675g of aluminum from 15^oC to 35^oC. (Specific Heat of aluminum is 0.902 J/g^oC)

Open Ended

The temperature of a piece of Metal X (specific heat of 0.724 J/g°C) with a mass of 95.4 g increases from 25.0°C to

48.0°C. How much heat did it take?

Open Ended

How much heat is added to 3.4 g of olive oil at 21°C if the temperature increases to 85°C? The specific heat of olive oil is 1.97 J/g°C

Open Ended

A piece of stainless steel with a mass of 1.55 g absorbs heat when its temperature increases by 178°C. If the specific heat of stainless steel is 0.491 J/g°C, how much heat was absorbed?

Poll

How confident are you that you can learn this by the end of the week?

• I already get it now, by the end of the week I will be a master.

• I am feeling pretty good about getting it with some more practice.

• This might not be my best week, but I don't think it will be too bad

• I have no idea what is happening