How does altitude affect the boiling point of water?

How does altitude affect the boiling point of water?

• Gather your data

Altitude (ft) Boiling Point (oF)

0 ft. 212.0º

1000 ft. 210.1º

2000 ft. 208.1º

3000 ft. 206.2º

4000 ft. 204.3º

5000 ft. 202.4º

6000 ft. 200.6º

7000 ft. 198.7º

8000 ft. 196.9º

9000 ft. 195.0º

10000 ft. 193.2º

Altitude (ft) Boiling Point (oF)

11000 ft. 191.4º

12000 ft. 189.7º

13000 ft. 187.9º

14000 ft. 186.1º

15000 ft. 184.4º

16000 ft. 182.7º

18000 ft. 179.2º

20000 ft. 175.9º

25000 ft. 167.8º

29000 ft. 161.5º

30000 ft. 160.0º

Altitude vs. Boiling Point of Water

http://www.engineeringtoolbox.com/boiling-points-water-altitude-d_1344.html

How does altitude affect the boiling point of water?

• Gather your data• Plot points representing the data on a grid

Plot the points using the data from the table.Scale the axes as appropriate.

How does altitude affect the boiling point of water?

• Gather your data• Plot points representing the data on a grid• Draw a curve (line) representative of the data points

Altitude (ft) Boiling Point (oF)

0 ft. 212.0º

1000 ft. 210.1º

2000 ft. 208.1º

3000 ft. 206.2º

4000 ft. 204.3º

5000 ft. 202.4º

6000 ft. 200.6º

7000 ft. 198.7º

8000 ft. 196.9º

9000 ft. 195.0º

10000 ft. 193.2º

Altitude vs. Boiling Point of Water

http://www.engineeringtoolbox.com/boiling-points-water-altitude-d_1344.html

Draw a line representing the data.

Pick 2 points on the graph and draw a line through those points.

0,212.0 and 10000,193.2

How does altitude affect the boiling point of water?

• Gather your data• Plot points representing the data on a grid• Draw a curve (line) representative of the data points• Label the graph• Title• Label the axes, including units on each axis

How does altitude affect the boiling point of water?

Altitude ( feet )

Boili

ng P

oint

( F

° )

Find an equation of the graphed line

y mx b slope and y interceptm b

Find the y-intercept of the line, b

How does altitude affect the boiling point of water?

Altitude ( feet )

Boili

ng P

oint

( F

° )

The y-intercept is 212Let b = 212

Find an equation of the line

y mx b slope and y interceptm b

The y-intercept of the line is b = 12

212y mx

Find an equation of the line

y mx b slope and y interceptm b

The y-intercept of the line is b = 12

212y mx Find the slope of the line, m

Find the slope of the line12

2 1

slopey y

mx x

Use the points: (0 , 212.0) and (10000,193.2)12

2 1

193.2 212.0slope

10000 0

18.8

100000.00188

slope 0.00188

y ym

x x

m

Find an equation of the line

y mx b slope and y interceptm b

The y-intercept of the line is b = 12

212y mx The slope of the line is m = -0.00188

0.00188 212y x

How does altitude affect the boiling point of water?

Altitude ( feet )

Boili

ng P

oint

( F

° )

The equation of the line is:y = -0.00188x + 212

How does altitude affect the boiling point of water?

Altitude ( feet )

Boili

ng P

oint

( F

° )

Boiling Point = 0.00188 Altitude + 212

The slope of the line is m = -0.00188

0.00188 212y x

What does that actually mean?

How does altitude affect the boiling point of water?

Altitude ( feet )

Boili

ng P

oint

( F

° )

rise 212 193.2 18.8

run 10,000

18.8slope =

10,000 ft.

The slope of the line is m = -0.00188

0.00188 212y x

What does that actually mean?

18.8 1.88slope = 0.00188 / ft.

10,000 ft. 1,000 ft.

This means that the boiling point of water is lowered by approximately 1.88° for every 1,000 ft. of elevation.

Notice the altered recipe and increased cooking time for high altitudes.

Why is the boiling point of water lowered at higher altitudes?

Because the air is thinner at higher altitudes, thus there is less pressure there.

What is the highest point on the Earth?

What is the highest point in the United States?

What is the highest point in Florida?

Mt. Everest at 29,029 ft.

Mt. McKinley at 20,322 ft.

Britton Hill in Walton County at 345 ft.

If you were to take a cup of water to a really high altitude, do you think it’s possible that water could boil at room temperature?

https://www.youtube.com/watch?v=Ks4VuXTTKmohttps://www.youtube.com/watch?v=XoOQNwcrDWE

At higher altitudes, the pressure is lower and consequently water boils at a lower temperature.

What do you think happens to the boiling point of water if you increase the pressure around it?

Using a pressure cooker increases the pressure around a liquid, which raises the boiling point of the liquid, allowing food to cook at a higher temperature, which causes the food to cook faster.

Exactly what is boiling, anyway?

A liquid boils at a temperature at which its vapor pressure is equal to the pressure of the gas above it. The lower the pressure of a gas above a liquid, the lower the temperature at which the liquid will boil.

http://www.chem.purdue.edu/gchelp/liquids/boil.html