Chem exam 2 review

greenhouse gases in atmospheres act as a one-way filter and allow ? to pass through and warm Earth’s center but prevent ? from radiating back out to space

visible light

heat energy

greenhouse gases allow ? to enter atmosphere and warm Earth’s surface but prevents heat generated by ? from escaping

sunlight

what would happen if greenhouse gases weren’t present

more heat would escape and would be about 60 degreed cooler

if greenhouse gases in atmosphere were to increase

temp would rise

rising CO₂ from burning fossil fuels are

90% of our energy

fossil fuels

natural gas, petroleum, coal

chemical reaction

process in which one of more substances are converted into one or more different ones

description of chemical reaction using symbols and formulas to represent elements and compounds involved

stoichiometric factor

mole ratio

conversion factor obtained from the stoichiometric coefficients in chem reaction

combustion reaction

a substance that combines with O₂ to form CO₂ and H₂O and emits heat

reactant on the

left

product on the

right

we use heat released by combustion of natural gas to

cook food and heat our homes

coefficients in a chemical equation specify the

relative amount of moles of each substance involved in reaction

stoichiometry

the study of numerical relationships between chemical quantities in a chemical reaction

limiting reactant

reactant that limits the amount of product in chem reaction/ makes least amount

theoretical yield

max amount of product that can be made in a chem reaction based on amount of limiting reactant

calculated quantity of product in reaction

actual yield

amount of product that was actually attained when carrying out reaction

percent yield formula

(Actual yield/ theoretical yield) * 100

percent yield

% of theoretical yield that was actually attained

what is a reactant in excess

any reactant that occurs in a quantity greater than is required to completely react with limiting reactant

alkali metals are ? metal and good examples of types of reaction that many metals undergo

most reactive

halogens are most active

nonmetals

compound containing C,H, O₂ will always form

CO₂ and H₂O

reactions of alkali metals with non metals are

vigorous, forceful, active, energetic

reaction of NaCl

glows

as we move down group of alkali metals with water the reactions become more

vigorous

halogens all react with many metals to from

metal halides

metals

lose electrons

halogens

gain electrons

H reacts with halogen to form

hydrogen halides

hydrogen Halies are covalent bonds and form ? when combined with water

acids

halogens interact with each other to form

inter halogen compounds

molecular gastronomy

a way of preparing food that involves chemistry

precipitation reaction

2 solutions/ homo mistures containing solid dissolved in liquid

aqueous solutions

solutions in which one component is water

common aqueous solutions

sea water, vinegar, watery environment within biological cells

solution

homogenous mixture of 2 or more substances

solvent

majority component

substance doing dissolving

solute

minority component

substance being dissolved

dilute solutions contain a

small amount of solute relative to solvent

concentrated solutions contain a

large amount of solute to solvent

M

mol/L

chemical reactions involving reactants are among the

most common and important

stock solutions

stored solutions in concentrated forms

M₁V₁=

M₂V₂

when diluting acids always add

concentrated acid to water

when diluting acids never add

water to concentrated solutions because heat generated may cause acid to splatter and burn skin

greenhouse gases in atmosphere allows

sunlight to enter earths atmosphere

warm earths surface

prevent some of heat generated by the sunlight from escaping

What determines Earth’s average temp

balance between ingoing and outgoing energy from sun

molarity/ molar concentration

amount of solute in moles per liter of solution

concentration tells moles of solute to

solvent

dilution

process of preparing a more solution by adding solvent to a more concentrated one

addition of solvent does not change

amount of solute in solution but does change solution concentration

it is very common to prepare a concentrated stock of solution of a solute then

dilute it to other concentrations as needed

electrolytes

substances that dissolve in water to form solutions that conduct electricity

strong electrolytes

dissociate completely into ions when dissolved in water

weak electrolyte

only partially ionizes into its component ions in solution and therefore conducts electricity weakly

acid

a molecular substance that ionizes in water to form H⁺ ions

strong acid

completely ionizes in water

weak acid

partially ionizes in water

strong acids are ?

strong electrolytes

non-electrolyte

a substance that dissolves in water to form a solution that does not conduct electricity

soluble ionic compounds and strong acids are

strong electrolyte solutions

soluble molecular compounds are

non electrolyte solutions

weak acids are

weak electrolyte solutions

when solid is put into liquid solvent, attractive forces that hold solid together compete with attractive forces between ?

solvant molecules particles that compose the solid

precipitation reactions

reactions in which a slid/ precipitate form when we mix 2 solutions

only ? form precipitates

insoluble

in precipitation reactions 2 solutions containing soluble compounds combine and ?

an insoluble compound precipitates

if both products are soluble ?

no reaction occurs and no precipitation occurs

if one or both of possible products are ?

insoluble a precipitation occurs

molecular formula

equation showing complete neutral formulas for each compound in the reaction as if they existed as molecules

in actual solutions of soluble ionic compounds dissolved substances are present as

ions

complete ionic equations

list that all ions present as reactants or products in chemical reactions

strong electrolytes are represented as a and weak electrolytes

component ion

aren’t

spectator ions

don’t participate in the reaction and appear unchanged

ionic equations only show the

species that actually change during the reaction

molecular equation

chemical equation showing complete neutral formulas for every compound in reactions

complete ionic equation

chemical equation showing all species that are actually present in solution

net ionic equations show only the

species that change during the reaction

in an acid base reaction (neutralization reaction) an acids reacts with a base and the 2 neutralize producing

H₂O

gas evolution reaction

gas forms resulting in bubbling

polyphonic acids contain more than one

insoluable proton and release them sequentially

Examples of acids in everyday life

citrus fruits

vinegar

Example of bases in everyday life

soap

baking soda

milk of magnesia

acid-base reactions generally form

water and ionic salt that remains dissolved in solution

titration

a substance in a solution of known concentration is reacted with another substance in a solution of unknown concentration

equivalence point

point of titration when number of moles of OH^- added equals number of moles of H⁺ initially in solution titration complete

in a gas evolution 2 aqueous solutions mix to form a

gaseous product that bubbles out of solution

oxidation reduction reaction/ redox reaction

reaction in which electrons transform form one reactant to other

oxidation

loss of electrons and increase in oxidation state

reduction

gains of electrons and decrease in oxidation state

the charge of a polyatomic ion is the charge ?

associated with ion as a whole

oxidation number/state

“charge” atom would have in a compound if all shared electrons were assigned to more electronegative atoms

redox

reactions in which electrons transfer from one to other and often involves reaction of substance with O₂

Oxidation state of atom in free element is

zero

Oxidation state of monoatomic ion

charge on ion

Sum of oxidation states of all atoms in neutral compound is ? or ?

zero

equal to charge on ion

in compound metals have positive ox state of

1a- 1

2a-2

F ox state

-1