Unit 1

Question 1

What are the rules for significant digits?

Answer 1

1. all non-zero digits are significant
2. all final zeros after the decimal point are significant
3. zeros between two other significant digits are significant
4. zeros used only for spacing the decimal point are not significant

Question 2

Multiplication and Division of SF

Answer 2

The answer has the same number of SF as the least number of SF in the question

Question 3

Addition and Subtraction

Answer 3

The answer must have the same precision as the least precise value in the question.

Question 4

Isotope

Answer 4

an atom of an element with a different number of neutrons than the original element

Question 5

Atomic Mass

Answer 5

The weighted average of the different isotopes of an atom

Question 6

Inorganic Chemistry

Answer 6

chemistry with molecules not based on a carbon chain

Question 7

Ion

Answer 7

An atom that does not have equal numbers of protons and electrons

Question 8

Ionic Compound

Answer 8

A neutral species that forms between a metal ion and a non-metal ion

Question 9

Covalent Compound

Answer 9

A neutral species with atoms bonded together by sharing electrons.

Question 10

Monatomic Ion

Answer 10

A single atom acting as an ion.

Binary ionic compounds are compounds of two monatomic ions.

Question 11

Polyatomic Ion

Answer 11

Several atoms covalently bonded together acting as one ion.

Question 12

What’s a mole?

Answer 12

6.02 x 10 ^ 23 atoms

Molar mass is the mass of one mole of a substance, with units in g mol-1.

Question 13

What’s formula mass?

Answer 13

Formula mass is substituted for molar mass in ionic compounds since they don’t form discrete molecules.

Question 14

How do you find percent composition?

Answer 14

mass of one element in a compound / mass of total compound x 100%

Question 15

Empirical Formula

Answer 15

the simplest ratio of the elements in a compound

Ionic compounds only have an empirical formula since they’re already in lowerst terms

Question 16

Molecular Formula

Answer 16

The actual number of elements present in a covalent compound.

Question 17

How do you find the formula from the percent composition?

Answer 17

Convert all mass percents to moles, then find the ratio of moles

Question 18

How do you find the molecular formula?

Answer 18

The molar mass of the compound must be compared to the molar mass of the empirical formula.

Question 19

Balancing Tips

Answer 19

1. Diatomic: H2, N2, O2, F2, Cl2, Br2, I2

2. Balance elements last

Question 20

What is stoichiometry?

Answer 20

Stoichiometry is the branch of chemistry that deals with calculating the amounts of reactants and products involved in a chemical reaction.

Question 21

Steps for a stoichiometric calculation?

Answer 21

1. Determine the balanced reaction
2. Convert the amount you are given into moles
3. Convert from moles of the known to moles of the unknown based on the coefficients in the balanced chemical reaction
4. Convert from moles of the unknown to the units required