General Chemistry Exam 2 with complete
solution verified 100% correct
How to find the mass of a molecule? - Answer - g molecule --> mol molecule --> Avogadro's #
Example:
(1 mol CO.01g CO2)
x
(6.022 x 10^23 CO2 molecules / 1 mol CO2)
OR (to organize the equation/steps)
(44.01g CO mol CO2)
x
(1 mol CO.022 x 10^23 CO2 molecules)
Mass Percent Composition
(Mass Percent) - Answer - (Mass of element X in 1 mol of compound /
Mass of 1 mol of the compound) x 100%
Example:
,(2 x molar mass Cl / molar mass CCl2F2) x 100%
How to calculate the number of moles of each element that are present in each sample? - Answer -
Example:
0.857g H x (1 mol H / 1.01 g H) = 0.849 mol H
6.86g O x (1 mol O / 16.00g O) = 0.429 mol O
[Divide each # of moles by fewest moles]
0.849 mol H / 0.429 = 1.98 => 2
0.429 mol O / 0.429 = 1
So, the empirical compound of Hydrogen and Oxygen is H2O
How to calculate Molecular Mass [n]
(After finding Empirical Formula and given Molar Mass in the problem)? - Answer - Molecular Mass [n]
=>
(molar mass / empirical formula molar mass)
Elemental Analysis - Answer - A method of obtaining Empirical Formulas for unknown compounds
(containing C and H) by burning a sample of the compound in pure oxygen and analyzing the products of
the combustion reaction.
What must be in equilibrium in a "balanced" chemical reaction? - Answer - 1.) The number of atoms
2.) The amount of mass
Organic Compounds - Answer - A compound composed of C and H and other elements: N, O, and S.
, Example: Methane (CH4)
Hydrocarbons - Answer - Organic Compounds composed of only C and H.
Alkanes, Alkenes, Alkynes (# of bonds)? - Answer - Alkanes =>
Hydrocarbons with single-bonded carbons
Alkenes =>
Hydrocarbons with double-bonded carbons
Alkynes =>
Hydrocarbons with triple-bonded carbons
Base Names for Hydrocarbons - Answer - meth = 1
eth = 2
prop = 3
but = 4
pent = 5
hex = 6
hept = 7
oct = 8
non = 9
dec = 10
The Greenhouse Effect - Answer - Greenhouse gases in the atmosphere act as a one-way filter.
They allow sunlight to pass through and warm Earth's surface.
solution verified 100% correct
How to find the mass of a molecule? - Answer - g molecule --> mol molecule --> Avogadro's #
Example:
(1 mol CO.01g CO2)
x
(6.022 x 10^23 CO2 molecules / 1 mol CO2)
OR (to organize the equation/steps)
(44.01g CO mol CO2)
x
(1 mol CO.022 x 10^23 CO2 molecules)
Mass Percent Composition
(Mass Percent) - Answer - (Mass of element X in 1 mol of compound /
Mass of 1 mol of the compound) x 100%
Example:
,(2 x molar mass Cl / molar mass CCl2F2) x 100%
How to calculate the number of moles of each element that are present in each sample? - Answer -
Example:
0.857g H x (1 mol H / 1.01 g H) = 0.849 mol H
6.86g O x (1 mol O / 16.00g O) = 0.429 mol O
[Divide each # of moles by fewest moles]
0.849 mol H / 0.429 = 1.98 => 2
0.429 mol O / 0.429 = 1
So, the empirical compound of Hydrogen and Oxygen is H2O
How to calculate Molecular Mass [n]
(After finding Empirical Formula and given Molar Mass in the problem)? - Answer - Molecular Mass [n]
=>
(molar mass / empirical formula molar mass)
Elemental Analysis - Answer - A method of obtaining Empirical Formulas for unknown compounds
(containing C and H) by burning a sample of the compound in pure oxygen and analyzing the products of
the combustion reaction.
What must be in equilibrium in a "balanced" chemical reaction? - Answer - 1.) The number of atoms
2.) The amount of mass
Organic Compounds - Answer - A compound composed of C and H and other elements: N, O, and S.
, Example: Methane (CH4)
Hydrocarbons - Answer - Organic Compounds composed of only C and H.
Alkanes, Alkenes, Alkynes (# of bonds)? - Answer - Alkanes =>
Hydrocarbons with single-bonded carbons
Alkenes =>
Hydrocarbons with double-bonded carbons
Alkynes =>
Hydrocarbons with triple-bonded carbons
Base Names for Hydrocarbons - Answer - meth = 1
eth = 2
prop = 3
but = 4
pent = 5
hex = 6
hept = 7
oct = 8
non = 9
dec = 10
The Greenhouse Effect - Answer - Greenhouse gases in the atmosphere act as a one-way filter.
They allow sunlight to pass through and warm Earth's surface.
