CH 1-4 Chem 111

What is the formula for mass?

density x volume

What is the formula for density?

mass / volume

Whats the difference between Celcius, Farhrenheit, and Kelvin?

Celsius and Kelvin degrees are the same size but Fahrenheit degrees are smaller than Celsius and Kelvin units.

Whats the formula for converting C to F?

9/5 x [C degree given] +32

Whats the formula for converting C to kelvin?

[C given degree] + 273.15

Which degree has no negative temperature values?

kelvin

Which unit is not ambiguos in signifcant figures?

cm

What is the range of C in temperature values?

100 - 0

What is the range of kelvin in temperature values?

373 - 273

What is the range of F in temperature values?

212 - 32

Addition or subtraction rules

the measurement with the fewest decimal places will have the same amount of decimal places in the anwser

Multiplication or division rules

The measurement with the fewest signficant figures will have the same amount of significant figures in the anwser

What happens in chemical reactions?

atoms are separated, combined, or rearranged, but they are not created or destroyed

You find volume by doing what?

using the water displacement method

What did the cathode ray reveal?

that electrons are present in all atoms

What is the plum pudding model?

a positively charged sphere with electrons littered about

What is a pure substance?

matter that has a fixed or definite composition

What is a mixture?

matter that contains two or more substances physically but not chemically mixed

What is a homogenous mixture?

made up of the same composition throughout

What is a heterogenous mixture?

made up of the non-same composition throughout

How can a sugar-water mixture be seperated?

evaporate the water to recover the sugar

How can an iron-sand mixture be seperated?

using a magnet to remove the iron

What is a pure substance?

something composed of only one type of atom

What is a compound?

something composed of two or more elements chemically combined in a fixed ratio

What is sublimation?

heat is absorbed, ice changed into gas

What is deposition?

heat is released, gas changes into ice

What is vaporization?

heat is absorbed, water changes into gas

What is condensation?

heat is released, gas changes into water

What is a physical change?

a change in state or shape without changing substance identity or composition

What is a chemical change?

a creation of new substances with different compositions and properties

What is an extensive property?

depends on the amount of matter and change when the amount changes

What is an intensive property?

do not depend on the amount of matter and remain the same even if the amount changes

What is atomic mass?

the average mass of an element’s naturally occurring isotopes, measured in amu

How to calculate atomic mass?

the percentages must be divided by one hundred as a section of the equation then the relative amu that is listed

How to calculate average atomic mass?

multiply the given amu by the percentage divided by a hundred

How to find number of moles of an element?

divide the mass given in grams by the molar mass of the element

How to find the number of atoms in an element?

divide the mass given in grams by the molar mass of the element and then multiply by avogadros number

What is a solution?

a homogeneous mixture of two or more substances

What is a solvent?

a larger amount in a solution

What is a solute?

a smaller amount in a solution

What does an aqueous solution use as a solvent?

water

Ernest Rutherford tested Thomson’s model by doing what?

directing positive particles at thin gold foil

What would happen after Ernest Rutherford tested Thomsons model if Thomson was right?

the particles would pass straight through, but some were deflected or bounced back

What was the result from Rutherfords experiment?

it was found that atoms have a small, dense, positively charged nucleus that deflects positive particles

What is the size of a proton compared to an electron?

about 1840 times more massive

Who is James Chadwick?

in 1932 he discovered neutral particles called neutrons in the nucleus of atoms by bombarding beryllium with energetic particles

From biggest to smallest what is the sizing of protons, neutrons, and electrons?

smallest → midsize → biggest

What does the atomic number mean?

number of protons in nucleus

What is the mass number?

number of protons plus number of neutrons

How to find number of electrons?

equals to number of protons

How is an isotope written?

with the mass number above the atomic number beside the element symbol

How to find amount of neutrons in an element?

subtract the mass number from the atomic number

What is a molecule?

two or more atoms bonded together

What is a diatomic molecule?

only two atoms

What is a cation?

postivively charged, loses electrons

What is an anion?

negatively charged, gains electrons

What is an ionic compound?

a compound with a zero-net charge because it is balanced

How to tell the percent composition by mass?

multiply the moles of an element by the molar mass of said element then divide by the molar mass of the compound then multiply by a hundred

How to determine the empirical formula of a compound using mass percentages?

divide each percentage by the molar mass of the element then divide all these anwsers by the smallest value, if anwsers are not whole numbers then multiply with same number until at least one can be rounded to a whole number

What does a combustion analysis do?

determines an empirical formula experimentally

How to find the molecular formula using a compounds percentages by mass

remove percentage sign and divide these numbers by the molar mass of its element then write the pseudo formula, divide by the smallest subscript and write the empirical formula then divide the molar mass by the empirical molar mass to get the number that should multiply the empirical formula version of the compound

What should you not change when balancing an equation?

subscripts

What represents number of moles in an equation?

coefficients

What is the formula for finding mass of a certain part of a product from given grams in an equation?

divide the given grams by the weight of the compound then multiply that by the amount of moles of the certain product then multiply by the molar mass of the moles the in question wanted portion of the original compound

What is a limiting reactant?

used up first and determines the amount of product formed

What is the formula for identifying the limiting reactant?

grams of one portion of the compound divided by its molar mass then divided by the moles of the same portion of the compound, done twice to two differeing portions of the compound and the one with the least amount in the end is the limiting one

How to calculate the mass of a compound formed?

calculate the already calculated moels by the molar mass of the compound

What is theoretical yield?

the maximum amount of product formed when the limiting reagent completely reacts

What is the formula for percent yield?

actual yield divided by theoretical yield multiplied by a hundred

What is the formula for finding out the theoretical yield of an element?

divide the given mass by the compounds molar mass then multiply by the moles of the in question element

How to write the formula for ionic compounds?

write the ions with their charges swapped and written as subscripts

How to name ionic compounds?

metal name first followed by the nonmetal ion with its name ending in ‘ide’

Transition metals, when naming, must always have what?

a roman numeral after the name to determine its charge

In writing formulas what must be done with polyatomic ions?

parentheses must be placed around the ion in question and the multiplying charge as a subscript outside these parenthesis

What are molecular compounds made of?

two or more nonmetals

Naming molecular compounds includes?

the first nonmetal name followed by the second with a ‘ide’ ending and use prefixes for both elements based on amount of atoms, omit mono for first element but not the second if it is an oxygen

Which type of compound will never need a charge in its name?

molecular compound

What is HCl(g) called?

hydrogen chloride

What is HCl(aq) called?

hydrochloric acid

How do you name acids?

hydro beginning then nonmetal root and ‘ic’ ending, all one word with the second word being acid

How do you name acids when there is a polyatomic acid?

the root name of the ion is the beginning and if the polyatomic has an ‘ate’ ending then the ending would be ‘ic’ but if the ion ends in ‘ite’ the ending should be ‘ous’, two words with the second being acid

How to name binary acids?

the beginning should be hydro plus base name of nonmetal element and ending with ‘ic’

What is a hydrate?

compounds with a specific number of water molecules attached

How to seperate a hydrate from its solution?

heating that removes the water which forms an anhydrous salt

What does anhydrous mean?

without water

What makes a strong electrolyte?

dissolves a hundred percent in water into ions, producing a solution that conducts electricity

What is hydration?

a process where water molecules surround ions in solution

What makes a weak elecetrolyte?

dissolves mostly as molecules and partially as ions; its solution conducts electricity weakly

What makes a nonelectrolyte?

dissolves in water without forming ions; its solution does not conduct electricity

Which compounds are insoluble?

carbonates (CO₃²⁻), phosphates (PO₄³⁻), chromates (CrO₄²⁻), sulfides (S²⁻), and hydroxides (OH⁻)

Which compounds are soluble?

compounds containing alkali metal ions (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) and the ammonium ion (NH₄⁺), nitrates (NO₃⁻), acetates (CH₃COO⁻), bicarbonates (HCO₃⁻), chlorates (ClO₃⁻), and perchlorates (ClO₄⁻), halides (Cl⁻, Br⁻, I⁻), and sulfates (SO₄²⁻)

Properties of acids include what?

sour taste, blue litmus paper turning red, a reaction with metals to form H2(g), a reaction with carbonates and bicarbonates to produce CO2(g), and aqueous solutions that conduct electricity

Properties of bases include what?

bitter taste, slippery sensation, turning red litmus paper blue, and aqueous solutions that conduct electricity

Arrhenius acid produces what in water?

H+ ions

Arrhenius base produces what in water?

OH- ions

Arrhenius definition can’t explain what?

bases that do not have OH-

What is a bronsted acid?

a proton donor

What is a bronsted base?

a proton acceptor

What does it mean to be amphoteric?

can act as both an acid and a base

What happens in a neutralization reaction?

an acid reacts with a base to produce water and a salt