Chemistry MYP Final

suspension

large, visual particles; block light, show Tyndall effect sometimes; heterogeneous mixture

solution

homogenous mixtures; solute + solvent; no Tyndall effect

colloid

microscopic particles; Tyndall effect; heterogeneous mixture

Tyndall Effect

scattering of light by suspended particles, making a beam of light visible

polarity

certain molecules (ex. water) have areas of partial + and partial - charges

hydrogen bond

NOT a full chemical bond

the positive area charge of one water molecule is attracted to the negative area of a different water molecule

electronegativity

attraction to electrons

cohesion

attraction between molecules in a liquid, causes droplets to form

adhesion

water sticks to polar substances

surface tension

allows objects of a higher density to float on water without sinking

density

the ratio of a substance’s mass to its volume

homogenous mixture

mixtures that are uniform throughout

solutions

heterogeneous mixture

mixtures where the composition is NOT uniform throughout

colloids

suspensions

solute

dissolved in the solvent

solvent

able to dissolve other chemical substances, or the solute

groundwater

water held underground in soil or in crevices of rock

aquifer

a body of permeable rock which can contain groundwater

non-polar

have identical electronegativities

ionic compounds

dissolve when placed in water, anion + cation separate and are attracted to positive and negative charges

polar

Is water polar or nonpolar?

partial positive

In a water molecule, does hydrogen have a partial positive or partial negative charge?

partial negative

In a water molecule, does oxygen have a partial positive or partial negative charge?

Investigation 1

paper clip should float on water but not alcohol

Investigation 4

Beaker A is water (ice floated)

Beaker B is alcohol (ice sank)

Investigation 5

more sugar should dissolve in warm water than cold

Investigation 6

Tyndall effect; beam through one and not the other. undissolved particles scatter light

Investigation 7

all saltwater solutions should conduct electricity and have a much higher conductivity measure than distilled water

surface water

Where does the most water come from in Baltimore City?

minerals

a naturally occurring chemical substance

ores

a naturally occurring solid material from which a metal or valuable mineral can be profitably extracted

The percent composition will depend on if something is mined or not

How is mining related to percent composition?

6.022 × 10²³

one mole

6.022 × 10²³

Avogadro’s number

add together the atomic masses of each element in the compound

How do you calculate molar mass?

Molar mass

the total of all of the atomic masses of an element added together

g/mol of a substance

extracting valuable minerals from their deposits through mining

What does extraction from an ore mean?

6.022 × 10²³ mole

How many atoms are present in one mole of a substance?

189.39 g/mol

What is the molar mass of Zn(NO₃)₂?

27.90%

Calculate the percent by mass of copper in the compound Cu(NH₃)₄SO₄

• the percent of mineral in the ore

• the percent of metal in the mineral

What two factors are used to determine if it is profitable to mine an ore?

Law of Conservation of Matter

matter cannot be created or destroyed

renewable resources

replenish themselves

sunlight, water, air, plants

examples of renewable resources

nonrenewable resources

used at a higher rate than it can be replenished

petroleum, minerals, metals, ores

examples of nonrenewable resources

solution concentration

amount of solute dissolved in a given amount of solvent

ppm

parts per million

molarity

the number of moles of solute per moles of solution

ionic compound

when atoms transfer electrons between each other, typically between metals and nonmetals

dissociate in water (cations and anions separate so it can dissolve)

polar covalent

two atoms with different electronegativities share

nonpolar covalent

share electrons equally

saturated

a solution is unable to dissolve or absorb any more of a solute

unsaturated

capable of absorbing or dissolving more of a solute

supersaturated

through heat, a substance dissolves more of a solute than the solution it can hold

solubility

the ability of a solute to dissolve a solvent

solubility curve

a graph indicating the solubility of a particular solute at different temperatures

metabolism

a complex series of interrelated chemical reactions that keep organisms alive

gas bubble trauma

when fish are exposed to supersaturated levels of dissolved gas and gas bubbles begin to form in the tissues

6.02 × 10²³

What is the total number of molecules in one mole of Nitrogen, N₂?

9.54 kg/m³

What is the density of water as a solid?

1.00 g/cm³

What is the density of water as a liquid?

.0048 g/L

What is the density of water as a gas?

Nonpolar compound

If two of the same elements are bonded together, is the compound polar or nonpolar?

Nonpolar

Is oil polar or nonpolar?

dependent variable

changes as a result of the change in the independent

independent variable

changed by the experiement by design (one thing)

controlled variable

keep them the same throughout the trials

polar compound

does not dissociate in water (dissolves without cations and anions separating)

sugar, rubbing alcohol

experimental group

gets the testing/experimental conditions

control group

does not get the experimental conditions

baseline group

Molarity, ppm, percent composition

What three ways can you measure concentration?