CHEM101 – Exam 1 study guide ch1-3 exam with questions and answers (100%
solved)
- consist of a combination of cations and anions
- the formula is usually the same as the empirical formula
- the sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero
- the most reactive metals (Li, Na, Mg, K, Ca, Rb, Sr, Cs, Ba, Al) and the most reactive nonmetals
(N, O, S, F, Cl, Br, I) as well as polyatomic ions combine to form thesel - ✔✔✔-ionic compounds
(salts)
- often a metal + nonmetal
- anion (nonmetal), add "-ide" to element name - ✔✔✔-things to remember about ionic
comoounds
(n x molar mass of element / molar mass of compound) * 100%
- n is the number of moles of the element in 1 mole of the compound - ✔✔✔-percent
composition
°F = (9/5) x °C + 32 - ✔✔✔-conversion of Celsius to Fahrenheit
~ 100 pm = 1 x 10⁻¹⁰ m - ✔✔✔-atomic radius
~ 5 x 10⁻³ pm = 5 x 10⁻¹⁵ m - ✔✔✔-nuclear radius
1. atom's positive charge is concentrated in the nucleus
2. proton (p) has opposite (+) charge of electron (-)
3. mass of p is 1840 x mass of e⁻ (1.67 x 10⁻²⁴ g) - ✔✔✔-conclusion of the Rutherford
Experiment
1. don't talk about Sig Figs...Any digit that is not zero is significant
,CHEM101 – Exam 1 study guide ch1-3 exam with questions and answers (100%
solved)
2. zeros between nonzero digits are significant
3. zeros to the left of the first nonzero digit are not significant
4. if a number is greater than 1, then all zeros to the right of the decimal point are significant
5. if a number is less than 1, then only the zeros that are at the end and in the middle of the
number are significant - ✔✔✔-roles of sig figs
1. Elements are composed of extremely small particles called atoms.
2. All atoms of a given element are identical, having the same size, mass and chemical
properties. The atoms of one element are different from the atoms of all other elements.
3. Compounds are composed of atoms of more than one element. In any compound, the ratio
of the numbers of atoms of any two of the elements present is either an integer or a simple
fraction.
4. A chemical reaction involves only the separation, combination, or rearrangement of atoms; it
does not result in their creation or destruction. - ✔✔✔-Dalton's Atomic Theory
1. free elements (uncombined state) have an oxidation number of zero
2. in monatomic ions, the oxidation number is equal to the charge on the ion
3. the oxidation number of oxygen is usually -2. In H₂O₂ and O₂²⁻ it is -1
4. the oxidation number of hydrogen is +1 except when it is bonded to metals in binary
compounds. In these cases, its oxidation number is -1.
5. Group IA metals are +1, IIA metals are +2 and fluorine is always -1
6. the sum of the oxidation numbers of all the atoms in a molecule or ion is equal to the charge
on the molecule or ion
7. oxidation numbers do not have to be integers. The oxidation number of oxygen in the
superoxide ion, O₂⁻, is -½ - ✔✔✔-rules for redox reactions
1. results should be reproducible by others
2. detailed research results should be reviewable
, CHEM101 – Exam 1 study guide ch1-3 exam with questions and answers (100%
solved)
3. conclusions should be reasonable and unbiased
4. "give credit when credit is due" - ✔✔✔-four basic rules of good science
1. write each quantity with the same exponent n
2. combine N₁ and N₂
3. the exponent, n, remains the same - ✔✔✔-scientific notation rules (addition/subtraction)
1. write the balanced molecular equation.
2. write the ionic equation showing the strong electrolytes completely dissociated into cations
and anions.
3. cancel the spectator ions on both sides of the ionic equation.
4. check that charges and number of atoms are balanced in the net ionic equation. - ✔✔✔-how
to solve net ionic equations
1. write the correct formula(s) for the reactants on the left side and the correct formula(s) for
the product(s) on the right side of the equation.
2. change the numbers in front of the formulas (coefficients) to make the number of atoms of
each element the same on both sides of the equation. Do not change the subscripts.
3. start by balancing those elements that appear in only one reactant and one product.
4. balance those elements that appear in two or more reactants or products.
5. check to make sure that you have the same number of each type of atom on both sides of the
equation. - ✔✔✔-how to balance chemical equations
1.008 amu - ✔✔✔-1 atom ¹H is equivalent to...
1.67262 x 10⁻²⁴
~ mass of a neutron ~1840 x mass e⁻ - ✔✔✔-mass of a proton
solved)
- consist of a combination of cations and anions
- the formula is usually the same as the empirical formula
- the sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero
- the most reactive metals (Li, Na, Mg, K, Ca, Rb, Sr, Cs, Ba, Al) and the most reactive nonmetals
(N, O, S, F, Cl, Br, I) as well as polyatomic ions combine to form thesel - ✔✔✔-ionic compounds
(salts)
- often a metal + nonmetal
- anion (nonmetal), add "-ide" to element name - ✔✔✔-things to remember about ionic
comoounds
(n x molar mass of element / molar mass of compound) * 100%
- n is the number of moles of the element in 1 mole of the compound - ✔✔✔-percent
composition
°F = (9/5) x °C + 32 - ✔✔✔-conversion of Celsius to Fahrenheit
~ 100 pm = 1 x 10⁻¹⁰ m - ✔✔✔-atomic radius
~ 5 x 10⁻³ pm = 5 x 10⁻¹⁵ m - ✔✔✔-nuclear radius
1. atom's positive charge is concentrated in the nucleus
2. proton (p) has opposite (+) charge of electron (-)
3. mass of p is 1840 x mass of e⁻ (1.67 x 10⁻²⁴ g) - ✔✔✔-conclusion of the Rutherford
Experiment
1. don't talk about Sig Figs...Any digit that is not zero is significant
,CHEM101 – Exam 1 study guide ch1-3 exam with questions and answers (100%
solved)
2. zeros between nonzero digits are significant
3. zeros to the left of the first nonzero digit are not significant
4. if a number is greater than 1, then all zeros to the right of the decimal point are significant
5. if a number is less than 1, then only the zeros that are at the end and in the middle of the
number are significant - ✔✔✔-roles of sig figs
1. Elements are composed of extremely small particles called atoms.
2. All atoms of a given element are identical, having the same size, mass and chemical
properties. The atoms of one element are different from the atoms of all other elements.
3. Compounds are composed of atoms of more than one element. In any compound, the ratio
of the numbers of atoms of any two of the elements present is either an integer or a simple
fraction.
4. A chemical reaction involves only the separation, combination, or rearrangement of atoms; it
does not result in their creation or destruction. - ✔✔✔-Dalton's Atomic Theory
1. free elements (uncombined state) have an oxidation number of zero
2. in monatomic ions, the oxidation number is equal to the charge on the ion
3. the oxidation number of oxygen is usually -2. In H₂O₂ and O₂²⁻ it is -1
4. the oxidation number of hydrogen is +1 except when it is bonded to metals in binary
compounds. In these cases, its oxidation number is -1.
5. Group IA metals are +1, IIA metals are +2 and fluorine is always -1
6. the sum of the oxidation numbers of all the atoms in a molecule or ion is equal to the charge
on the molecule or ion
7. oxidation numbers do not have to be integers. The oxidation number of oxygen in the
superoxide ion, O₂⁻, is -½ - ✔✔✔-rules for redox reactions
1. results should be reproducible by others
2. detailed research results should be reviewable
, CHEM101 – Exam 1 study guide ch1-3 exam with questions and answers (100%
solved)
3. conclusions should be reasonable and unbiased
4. "give credit when credit is due" - ✔✔✔-four basic rules of good science
1. write each quantity with the same exponent n
2. combine N₁ and N₂
3. the exponent, n, remains the same - ✔✔✔-scientific notation rules (addition/subtraction)
1. write the balanced molecular equation.
2. write the ionic equation showing the strong electrolytes completely dissociated into cations
and anions.
3. cancel the spectator ions on both sides of the ionic equation.
4. check that charges and number of atoms are balanced in the net ionic equation. - ✔✔✔-how
to solve net ionic equations
1. write the correct formula(s) for the reactants on the left side and the correct formula(s) for
the product(s) on the right side of the equation.
2. change the numbers in front of the formulas (coefficients) to make the number of atoms of
each element the same on both sides of the equation. Do not change the subscripts.
3. start by balancing those elements that appear in only one reactant and one product.
4. balance those elements that appear in two or more reactants or products.
5. check to make sure that you have the same number of each type of atom on both sides of the
equation. - ✔✔✔-how to balance chemical equations
1.008 amu - ✔✔✔-1 atom ¹H is equivalent to...
1.67262 x 10⁻²⁴
~ mass of a neutron ~1840 x mass e⁻ - ✔✔✔-mass of a proton
