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Phases And Phase Change Homework Answers

 Unit 2b: Energy

  Example of a Heating Curve for a Substance

**To analyze a cooling curve, read the below heating curve in reverse starting at segment E and ending at segment A**

 

 

For any phase change that overcomes intermolecular forces to move the molecules apart, potential energy increases while kinetic energy remains constant. Phase changes that fit this description include: Fusion, vaporization and sublimation.

 

For any phase change that must require a cooling that allows molecules to move together another and strengthen intermolecular forces, potential energy decreases while kinetic energy remains constant. Phase changes that fit this description include: Solidification, condensation and deposition. 

 

 

VIDEOS

Calorimetry Formula Tutorial Video:  https://m.youtube.com/watch?v=L9spPoot3fU

Please watch the above video and take notes on how to calculate the energy that influences a temperature change.

 

 Notes

 

Introduction to Energy and Heat 2017

 Phase Changes 2017

  Calorimetry 2017

 Heating and Cooling Curve Notes 2017

Heating Curve Particle Diagram Notes 2017

Heat Calculations of Phase Changes 2017

 

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Reg Chem Phase Change Activity Sheet  Assigned as CW on 10/12-10/13

Reg Chem Phase Change Activity Sheet Answer Key 

 

R-Chem Energy Changes HW Sheet Answer Key Assigned as HW on 10/13

 

Calorimetry POGIL Assigned as CW on 10/16

Calorimetry POGIL  Answer Key

 

Calorimetry Classwork Answer Key Assigned as CW on 10/18

 

Calorimetry HW Answer Key Assigned as HW on 10/18

 

Temperature and Phase Change Graphing Answer Key Assigned as CW on 10/18-10/19

 

R-Chem Heating Curves Introduction Questions Answer Key Assigned as CW on 10/19

 

R Chem Heating Curves HW Packet Answer Key Assigned as HW on 10/19

 

R Chem Heating Curves Packet Practice Questions Answer Key Assigned as CW on 10/20 and 10/23

 

R Chem Temperature Phases and Energy MC WS Answer Key Assigned as HW on 10/20

 

Heat of Phase Change Calculations Answer Key Assigned as HW on 10/23

 

Mixed Heat Calculations Answer Key Assigned as CW on 10/24

 

Heating Curve Calculations Answer Key Assigned as HW on 10/24

 

Matter and Energy Group Stations Review Questions Assigned as CW on 10/25

 

Matter and Energy Group Stations Review Answer Key

 

Matter and Energy Review Packet  Distributed on 10/25

Matter and Energy Review Packet Answer Key

 

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Unit 2a: Matter

Matter and Energy Vocabulary Sheet

 

Notes

Substances and Mixtures Notes 2017

Physical and Chemical Changes 2017

 Elements, Compounds and Mixtures 2017

 Phases of Matter Notes 2017

Separating a Mixture Notes 2017

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Reg Chem Matter WS and Answer Key

Assigned as HW on 9/28/17

 

Castle Learning Matter HW PDF Copy-  Assigned as HW on 9/29/17

 

Castle Learning Matter HW Answer Key-
1) 2   Elements can NEVER be decomposed chemically.
2) 4   Solids have a regular geometric pattern.
3) 2   Density is an intensive property that is the same for any sample size of a substance.
4) 3   Gases have indefinite shape and indefinite volume
5) 4
6) 4   Any reaction indicates a chemical change has occurred.
7) 2   Solids are fixed particles in regular geometric pattern.
8) 3   Compounds can be decomposed chemically. All other choices are elements.
9) 4
10) 4 Elements can NEVER be decomposed chemically. All other choices are compounds.
11) 1 Calcium= Ca, element. Diamond is made of Carbon= C, element. Uranium= U, element.
12) 1
13) 1
14) 2
15) 4
16) Sample C contains a diatomic element (Fluorine= F2) and a binary compound (Hydrogen chloride= 2 different elements)
17) Sample A is a binary compound and substance while sample B is a mixture of two different binary compounds. (2 substances are present in sample B, while only 1 substance is present in sample A)
18) Heterogeneous
19) NaCl(aq), the particles of salt and water and evenly distributed to give a uniform appearance.
20)  NH4NO3 (s) dissolves in water making it aqueous, NH4NO3 (aq). All aqueous solutions are homogeneous mixtures.
21) Mixture 1= homogenous because it is colorless with no visible solid on the bottom of the beaker. You cannot see the different components.
Mixture 2= heteregeneous because you can see the black solid on the bottom of the beaker. All components are visible.
22)  1
23) 4
24) 2 (aq)= aqueous= dissolved in water. All substances dissolved in water are a homogenous mixture.
25) 4

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Particle Diagram Worksheet Key  Assigned as HW on 10/3/17

 

Regents Chem Particle Diagrams Answer Key Assigned as CW on 10/3/17

 

R Chem MC Matter Worksheet Answer Key Assigned as HW on 10/4/17

 

R Chem Phases of Elements Activity Answer Key Assigned as CW on 10/5/17-10/6/17

 

Regents Chemistry Matter Exam Review 2017 Assigned as HW on 10/6/17

Matter Exam Review 2017 Answer Key

 

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OLD MATERIALS


Worksheet Answer Keys

 

Heating Curves and Calculations HW Answer Key  Assigned as HW on 10/19/16

 

Calculating the Specific Heat of a Metal Answer Key  Assigned as CW on 10/21/16

 

Matter and Energy Review Packet 2016 with Answer Key Attached  Distributed on 10/24/16

There is a mistake in the answer key. #26 should be 1254J that rounds to 1250J of heat, NOT 1340J as shown in the printout of the answer key.

 


 

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 Matter Unit Materials

 

Matter Textbook Questions Answer Key Assigned as HW on 9/22/16 and 9/27/16

 

Particle Diagram Worksheet Key  Assigned as HW on 9/23/16

 

States of Matter Worksheet Answer Key Assigned as classwork on 9/28/16

 

Castle Learning Matter Review Packet- To be given out in class 9/29/16

 

 Castle Learning Matter Review Answer Key- Given out in class 9/29/16
1) 2   Elements can NEVER be decomposed chemically.
2) 4   Solids have a regular geometric pattern.
3) 2   Density is an intensive property that is the same for any sample size of a substance.
4) 3   Gases have indefinite shape and indefinite volume
5) 4
6) 4   Any reaction indicates a chemical change has occurred.
7) 2   Solids are fixed particles in regular geometric pattern.
8) 3   Compounds can be decomposed chemically. All other choices are elements.
9) 4
10) 4 Elements can NEVER be decomposed chemically. All other choices are compounds.
11) 1 Calcium= Ca, element. Diamond is made of Carbon= C, element. Uranium= U, element.
12) 1
13) 1
14) 2
15) 4
16) Sample C contains a diatomic element (Fluorine= F2) and a binary compound (Hydrogen chloride= 2 different elements)
17) Sample A is a binary compound and substance while sample B is a mixture of two different binary compounds. (2 substances are present in sample B, while only 1 substance is present in sample A)
18) Heterogeneous
19) NaCl(aq), the particles of salt and water and evenly distributed to give a uniform appearance.
20)  NH4NO3 (s) dissolves in water making it aqueous, NH4NO3 (aq). All aqueous solutions are homogeneous mixtures.
21) Mixture 1= homogenous because it is colorless with no visible solid on the bottom of the beaker. You cannot see the different components.
Mixture 2= heteregeneous because you can see the black solid on the bottom of the beaker. All components are visible.
22)  1
23) 4
24) 2 (aq)= aqueous= dissolved in water. All substances dissolved in water are a homogenous mixture.
25) 4

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Particle Diagram Homework Answer Key  9/29/15

 

Answers to Energy Changes Homework Assigned 10/7/15

 

Calorimetry POGIL Answer Key  Completed in class 10/8/15-10/9/15

 

Temperature HW Answer Key Assigned as HW 10/8/15 

 

Energy Calculations WS 2 Answer Key  Assigned as HW 10/9/15- Odds only

 **#7 does not use Q=mcT but uses Q=mHv because the process of vaporization is a phase change and phase changes occur at constant temperatures as any heat being added is used towards spreading molecules apart from each other.

 

Energy, Phases and Temperature Regents MC Answer Key Assigned as HW 10/13/15

 

Heat of Fusion and Vaporization Calculations Answer Key  Assigned as classwork 10/16/15

 

Mixed Heat Calculations Answer Key Assigned as HW 10/16/15

 

Heating Curves Classwork Answer Key  Assigned as classwork 10/19/15

 

EXTRA PRACTICE

All matter is made from atoms. Every substance (oxygen, lead, silver, neon ...) has a unique number of protons, neutrons, and electrons. Oxygen, for example, has 8 protons, 8 neutrons, and 8 electrons. Hydrogen has 1 proton and 1 electron. Individual atoms can combine with other atoms to form molecules. Water molecules contain two atoms of hydrogen H and one atom of oxygen O and is chemically called H2O. Oxygen and nitrogen are the major components of air and occur in nature as diatomic (two atom) molecules. Regardless of the type of molecule, matter normally exists as either a solid, a liquid, or a gas. We call this property of matter the phase of the matter. The three normal phases of matter have unique characteristics which are listed on the slide.

Solid

In the solid phase the molecules are closely bound to one another by molecular forces. A solid holds its shape and the volume of a solid is fixed by the shape of the solid.

Liquid

In the liquid phase the molecular forces are weaker than in a solid. A liquid will take the shape of its container with a free surface in a gravitational field. In microgravity, a liquid forms a ball inside a free surface. Regardless of gravity, a liquid has a fixed volume.

Gas

In the gas phase the molecular forces are very weak. A gas fills its container, taking both the shape and the volume of the container.

Fluids (Liquids and Gases)

Liquids and gases are called fluids because they can be made to flow, or move. In any fluid, the molecules themselves are in constant, random motion, colliding with each other and with the walls of any container. The motion of fluids and the reaction to external forces are described by the Navier-Stokes Equations, which express a conservation of mass, momentum, and energy. The motion of solids and the reaction to external forces are described by Newton's Laws of Motion.

Any substance can occur in any phase. Under standard atmospheric conditions, water exists as a liquid. But if we lower the temperature below 0 degrees Celsius, or 32 degrees Fahrenheit, water changes its phase into a solid called ice. Similarly, if we heat a volume of water above 100 degrees Celsius, or 212 degrees Fahrenheit, water changes its phase into a gas called water vapor. Changes in the phase of matter are physical changes, not chemical changes. A molecule of water vapor has the same chemical composition, H2O, as a molecule of liquid water or a molecule of ice.

When studying gases , we can investigate the motions and interactions of individual molecules, or we can investigate the large scale action of the gas as a whole. Scientists refer to the large scale motion of the gas as the macro scale and the individual molecular motions as the micro scale. Some phenomenon are easier to understand and explain based on the macro scale, while other phenomenon are more easily explained on the micro scale. Macro scale investigations are based on things that we can easily observe and measure. But micro scale investigations are based on rather simple theories because we cannot actually observe an individual gas molecule in motion. Macro scale and micro scale investigations are just two views of the same thing.

Plasma - the "fourth phase"

The three normal phases of matter listed on the slide have been known for many years and studied in physics and chemistry classes. In recent times, we have begun to study matter at the very high temperatures and pressures which typically occur on the Sun, or during re-entry from space. Under these conditions, the atoms themselves begin to break down; electrons are stripped from their orbit around the nucleus leaving a positively charged ion behind. The resulting mixture of neutral atoms, free electrons, and charged ions is called a plasma. A plasma has some unique qualities that causes scientists to label it a "fourth phase" of matter. A plasma is a fluid, like a liquid or gas, but because of the charged particles present in a plasma, it responds to and generates electro-magnetic forces. There are fluid dynamic equations, called the Boltzman equations, which include the electro-magnetic forces with the normal fluid forces of the Navier-Stokes equations. NASA is currently doing research into the use of plasmas for an ion propulsion system.


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