Chemistry 2

Matter

• solid
• liquid 
• gas

a fixed shape and volume

a fixed volume but not shape. molecules are free flowing

does not have fixed shape or volume

• property that describes its physical apperance
• ex) color, odor, density, boiling/melting points
• and descriptive terms and numbers

• describes a compouns ability to form a new substance. Also what it is made up of.
• ex). Iron can form rust. (what its made up of or what it turns into)

changes in the physical characteristics of a compound but not in its chemical composition. (What you start with is what you end with) ex.) phase changes

change in the chemical composition of your compound. Always changes your physical properties. (end up with something different than what you started with)

• fundamental units of all matter. 
• -can not be broken down into a new substance
• -composed of single type of atom.
• -always pure

• chemical combinations of elements.
• -made up from elements
• -can be broken into the elements which compose them
• -have physical and chemical properties different from the elements that compose them.
• -can be pure but not always

• has variable composition more than one thing is found in it. 
• -are not chemical combinations
• -are not pure

• Solution
• -(Homogencous) is uniform throughout and can only see one thing. Has two parts a) Solvent-does dissolving b)solute- thing that is being dissolved
• Heterogenous Mixture
• -is not uniform. can see different parts
• -does not contain a solvent or solute

• always has the same composition. Only one thing present.
• -elements are always pure
• -are compounds only when they are by themselves

• A seperation of mixtures that can only be used on heterogenous mixtures. 
• -pour through a filter, liquid goes through, solid stays in filter

• A seperation of mixtures that can be used on both homo and hetero mixtures. (best for homo)
• -Heat solution to boil point to produce steam, condense steam by a cold tube of H2O, condensed steam drips into a new beaker as pure liquid, and salt stays behind. 

Capasity to do work

moving and object from point A to point B

• Flow of energy due to a temperature difference.
• -Exothermic- evolution of heat (lighting a match)
• -Endothermic- heat is absorbed. (melting ice)

• the amount of energy required to raise 1 gram of H2O 1 degree celcius. -Joule--SI unit of energy
• 1 calorie = 4.184 J

• The amount of energy to raise 1 gram of any substance 1 degree Celcius
• J/g0C

• Q= energy required (J)
• S= specific heat (J/g0C)
• M=mass (g)
• AT=change in temperature (C) (Final temp - initail temp)
•    - never use specific heat to determine # of sig figs

• Multiplying and Dividing= number of smallest sig figs 
• Adding and Subtracting= smallest # of decimal places 

• -Go to last sig fig. Number to right determines how you should round. If it's greater than 5 round up, If it's less than 5 leave it the same. 
• - If the number to the right is 5, then look the number to the right of that 5. If there is a number there other than 0, round up.
• -If the number after 5 is 0, or there is not a number, look back at your last sig fig. If your last sig fig is even, leave it the same. If it is odd, round up.