+

Solids, Liquids, and Gases

UNIT 8

+Today’s Objectives

■ Describe the properties of solids, liquids, and gases.

■ Calculate the energy needed to heat a substance from one temperature to another (Specific Heat).

q = mCpΔT■ Metals

■ Water

+IN LEARNING TEAMS…

You Will Investigate

1. Properties of States of Matter (Venn Diagram)2. What Determines State of Matter? (Kinetic Energy)3. What is Specific Heat4. Solving problems with

q = mCp ΔT5. Heating/Cooling Curve

15 mins - stop at stop sign

+Be Sure You Know These Terms:

■ Sublime - go from solid to gas

■ Deposition – go from a gas to a solid

■ Melt – Solid to liquid

■ Freeze – liquid to solid

■ Vaporize – liquid to gas(Boil/evaporate)

■ Condense – gas to liquid

■ Fluid – particles can “flow” over each other

■ Diffuse – spread into available volume

+Other Terms You Should Know….

■Compressible: force into less space(i.e. Balloon)

■Diffuse: move to area of less concentration(i.e. food coloring in water/perfume)

+Changes in Phase

+Transition processes

+Phase Characteristics

+What determines the state of matter?

■ Gases have the most kinetic energy.

■ Liquids have medium.

■ Solids have the least kinetic energy.

+Create a table with 3 headings –SOLID LIQUID GAS--Categorize the following into these categories

■ Rigid

■ Definite shape

■ No diffusion

■ Not compressible

■ Definite Volume

■ Takes up space

■ Particles Move b/cof their kinetic energy

■ Sublime

• Fluid

• No Definite Shape

• Diffusion

• No definite volume

• Compressible

• Has Mass

• Melt

• Condense

▪ Evaporates

▪ Deposition

▪ Freeze

▪ Boil

+CHECK

■ Rigid (s)

■ Definite shape (s)

■ No diffusion (s)

■ Not compressible (s, l)

■ Definite Volume (s, l)

■ Takes up space (s, l, g)

■ Particles Move b/cof their kinetic energy (s, l, g)

■ Sublime (s)

• Fluid (l, g)

• No Definite Shape (l, g)

• Diffusion (l, g)

• No definite volume (g)

• Compressible (g)

• Has Mass (s, l, g)

• Melt (s)

• Condense (g)

▪ Evaporates (l)

▪ Deposition (g)

▪ Freeze (l)

▪ Boil (l)

+ Kinetic energy and Potential Energy

Kinetic Energy – KE : Energy due to the motion of atoms or compounds

■Temperature : A of the measure of the average kinetic energy particles in a sample of matter

Potential Energy – PE : Energy due to the structure of the atoms or compounds

+Temperature

Temperature : A measure of the average kinetic energy of the particles in a sample of matter

As Temperature increases,

Motion increases and

Kinetic Energy increases

+

+Objective

■ Calculate the energy needed to heat a substance from one temperature to another (Specific Heat).

+Specific Heat

■ The specific heat , Cp of a substance is the amount of energy required to increase the temperature of 1 gram of a substance by 1°C.

■ Note! Every substance has a unique specific heat. (See NCDPI reference tables, p. 1)

+

+How to calculate the energy involved in a temperature change.q=mCpΔT

■q – energy (joules)

■m – mass (grams)

■Cp – specific heat (or specific heat capacity)■ΔT – change in temperature (final temp –initial temp)

Heating is ENDOTHERMIC and ΔT is (+) positiveCooling is EXOTHERMIC and ΔT is (-) negative

Copy This Into Your Notes !!!

+EXAMPLE 1■ How many joules of heat are needed to raise the

temperature of 10.0 g of aluminum from 22°C to 55°C, if the specific heat of aluminum is 0.90 J/g°C?

q=mCpΔTq = xM = 10.0 gCp = 0.90 j/goCΔT = 55 – 22 = 33Substitute and solve

297 J

+EXAMPLE 2

■ Calculate the SPECIFIC HEAT of a piece of wood if 1500.0 g of the wood absorbs 6.75 × 104 joules of heat, and its temperature changes from 32°C to 57°C.

1.8 J/goC

+ EXAMPLE 3What is the final temperature of a 50.0 g piece of glass if it absorbs 5275 joules of heat and its specific heat capacity is 0.50 J/g°C? The initial temperature of the glass is 20.0°C. *** Remember that ΔT = Final Temp – Initial Temp***

231oC

+You Try

■ What is the specific heat of silicon if the temperature of a 4.11 g sample of silicon is increased by 3.8 oC when 11.1 J of heat is added?

■ If 40.5 J of heat is added to a 15.4 g sample of silver, how much will the temperature increase by? The specific heat of silver is 0.235 J/goC.

+What happens when a substance changes states (solid, liquid, gas) of matter by either - HEATING or

COOLING the substance ?

+What happens when you heat a substance?

■ Two possible things can happen:

■ The substance changes temperature (Kinetic Energy)

OR

■ The substance changes state of matter (Potential Energy)

■ NEVER both at one time.

■ This can be represented by a heating curve or cooling curve

For example:

a piece of ice either changes temp OR melts

+Click below to see an animated heating curve for water

http://www.kentchemistry.com/links/Matter/HeatingCurve.htm

You’ll need to scroll down on the webpage to see the animated graph. Pay close attention to the states of matter on the graph and the animated particles at the top. We’ll be doing LOTS of math using this heating curve as you can tell by all the formulas ☺

+■HEATING CURVE - A graphical representation

of the temperature and energy involved in heating a substance. PROCESS IS ENDOTHERMIC

Copy This Into Your Notes !!!

+■COOLING CURVE – A graphical representation of the temperature and energy involved in cooling a substance. PROCESS IS EXOTHERMIC

Copy This Into Your Notes !!!

+

+Phase Change Calculations -

WATER ONLY!!!

+

+Phase Change Calculations (Water)

■ How much energy is required to increase the temperature of 5 g of water from 15oC to 100oC?

+Phase Change Calculations (Water)

■ How much energy is required to increase the temperature of 23.5 g of water from -15.6oC to 0oC ?

+You Try It!!

■ How much energy is RELEASED to when the temperature of 23.5 g of water decreases from 125oC to 100.5oC ?

+Today’s Objectives

■ Describe the properties of solids, liquids, and gases.

■ Calculate the energy needed to heat a substance from one temperature to another (Specific Heat).

■ Metals

■ Water

+CLASSWORK / HOMEWORK:

Begin preparation for Thursday Quest on Stoichiometry

+Exit Ticket

(1) What mass of water can be heated from 25.0° C to 50.0° C by the addition of 2825 J?

(2) How much heat is needed to raise a 300 g piece of aluminum from 30.°C to 150°C? (use reference table for specific heat)

(3) It takes 487.5 J to heat 25 grams of a substance from 25 °C to 75 °C.

(a) What is the specific heat in Joules/g·°C?

(b) What two metals could this substance be?

(Use your reference table)