Tuesday, November 30, 2010

Homework 10 Part 2

1. You divide the mass of the solute by the amount of solution. It is measured in moles. So 2moles/4 lters of liquid= solution of .5 mol/L
2.It shows the characteristics and properties of the substance easier.
3.amount of solute, temperature, pressure.
4.Solubility is dependent on temperature. It takes heat to make particles move and break apart.
5.Because it shows the characteristic property of matter.

Homework 10 Part 1

1. Solution: a mixture in which a solute is dissolved into a solvent.
    Colloid: a mixture in which all substances are evenly spaced microscopically.
    Suspension: a mixture with solid particles that are bigger than one micrometer mixed with other substances. A suspension will eventually settle.
2. They separate, and are surrounded by other solvent fluids.
3. They cause the freezing point to lower and the melting point to raise. Ex. Salt on an icy road.
4. It would be a solution because the food-coloring(solute) into the universal solvent (water)
5. They raise the boiling point and lower the freezing point.

  

Friday, November 19, 2010

Correction Part 2

Ok, I changed my mind again......
My new answer for the AMount of Heat need is 209,000J, not 109,0000.. Sowwy for the mistake

Test 9

How is thermal energy related to temperature and heat?
Thermal Energy is the energy of particles in an object when they move around because of temperature and heat. Heat is the transfer of one thing to another, using radiation, convection, or conduction. Temperature is the measurement and expression of thermal energy and heat.


Why do some materials get hot more quickly than others?
Everything has a specific heat measurement. Specific heat is the amount of energy need to change a substance in temperature. Things that have higher specific heat need more energy and time to heat up than substances with low specific heats.


What are the three forms of heat transfer? Please describe each.
In a nutshell, the three forms of heat are conduction, convection, and radiation. Conduction is the transfer of heat through substances when they are not moving. An example of this is me holding a cold rock and it receiving heat. Convection is the movement of heat through molecules of fluids.
An example of this is a pot of water boiling. Radiation is the release and movement of heat through electromagnetic waves. An example of this would be a microwave.


How much heat is required to raise the temperature of 5kg's of water by 10kg's?
(turn in answer)

5. Tent or Fire?
I would choose a tent. The best way to stay warm is to trap the heat instead of created mass amounts of it. If you use your body heat and trap it using layers and a tent, then you will be able to stay warmer than standing near a large heat source, for that source's heat is expelled, and little of the heat actually reaches you.

Correction

On my homework, for one of my answers, i said fire in the beginning. I really meant tent. Sowwy!!!!

Thursday, November 18, 2010

Homework 9 Part II

IV.3. Because all of the energy is used to change the form of matter, so there is not enough thermal energy to melt the substance.
IV.4 As thermal energy increases, the particles vibrate, and the crystalized structure is broken, causing it to turn into a liquid.
IV.5 A potato has a lot of water. When water is heated, it expands. So the expansion causes the pressure to build up. If you don't poke holes in it, it will EXPLODE!!!!!

V.1Heat is transferred from the source, through the "working body" of the engine, to the sink, and in this process some of the heat is converted into work by exploiting the properties of a working substance (usually a gas or liquid). -->  http://en.wikipedia.org/wiki/Heat_engine
V.2 They heat up differently. One uses insulators whilst the other uses convection. Although they both use heat to work.
V.3 External Combustion Engines heat up more.
V.4 Gas to a liquid.... Condensation
V.5 The cold would not escape, the heat would move in pushing the air out and making it hotter.

Wednesday, November 17, 2010

HomeWork 9, Bring the Heat!!!!! part 1

I.1 Fahrenheit, Celsius, and Kelvin.
I.2 Thermal Energy is the energy released when particles move quickly. Temperature is the expression and measurement of thermal energy and heat. Heat is the transfer of thermal energy from one thing to another.
So thermal energy controls heat and temperature, heat is the transfer of thermal energy changing temperature, and temperature is the measurement of the two, usually using thermometers.
I.3 Specific heat is the amount of energy needed to change a substance in temperature. If something has a high specific heat, then it needs a large amount of energy to change the temperature.
I.4 When you hold an ice cube, your hand transfers your body heat from your hand to the ice cube, causing it to exceed its melting point, turning it into a liquid.
I.5 Everything has a different specific heat. The lower it is, the quicker it will heat up. So the reason some things heat quicker is because they have a low specific heat. There are other factors such as conduction, but that is the main reason.

II.1 The mercury in the thermometers expand when it increases, causing the mercury to rise, hence the rising liquid within them.
II.2 They all give value of temperature. Celsius is based off of the boiling and freezing point of water. Kelvin is based off of absolute zero, while Fahrenheit is based of the freezing and melting point of a mixture of salt, water, and ice.
II.3 41 degrees F
II.4 460 degrees C
II.5 109,000 J

III.1 Conduction, Radiation, Convection
III.2 Hot to Cold. Always. Always.
III.3 Conductors transfer heat very well. Insulators trap and do not transfer heat.
III.4 Conductor. This is because metals are usually good conductors and heat travels through them very easily.
III.5 I would choose a fire. The best way to stay warm is to trap the heat instead of created mass amounts of it. If you use your body heat and trap it using layers and a tent, then you will be able to stay warmer than standing near a large heat source, for that source's heat is expelled, and little of the heat actually reaches you.

IV.1 Temperature, Pressure, and Heat Energy.
IV.2 It heats up, and eventually melts or burns.

II.3