Exam (elaborations)
General Chemistry Exam 2024/2025 Questions With Completed & Verified Solution.
- Course
- Institution
General Chemistry Exam 2024/2025 Questions With Completed & Verified Solution.
[Show more]
Content preview
General Chemistry Exam 2How to find the mass of a molecule? - ANS 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) - ANS (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? - ANS
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)? - ANS Molecular Mass
[n] =>
,(molar mass / empirical formula molar mass)
Elemental Analysis - ANS 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? - ANS 1.) The number of atoms
2.) The amount of mass
Organic Compounds - ANS A compound composed of C and H and other elements: N, O, and
S.
Example: Methane (CH4)
Hydrocarbons - ANS Organic Compounds composed of only C and H.
Alkanes, Alkenes, Alkynes (# of bonds)? - ANS Alkanes =>
Hydrocarbons with single-bonded carbons
Alkenes =>
Hydrocarbons with double-bonded carbons
Alkynes =>
Hydrocarbons with triple-bonded carbons
Base Names for Hydrocarbons - ANS meth = 1
eth = 2
prop = 3
but = 4
pent = 5
hex = 6
hept = 7
oct = 8
non = 9
dec = 10
The Greenhouse Effect - ANS Greenhouse gases in the atmosphere act as a one-way filter.
They allow sunlight to pass through and warm Earth's surface.
Prevent heat energy from radiating back out into space.
, Stoichiometry - ANS The numerical relationships between the amount of reactants and the
amount of products in a balanced chemical equation.
Coefficients in a Chemical Reaction (function) - ANS The amounts (in moles) of the reactants
and the products in a chemical reaction.
Limiting Reactant (Reagent) - ANS The reactant that has the smallest stoichiometric amount in
a reactant mixture and hence limits the amount of product in a chemical reaction.
The reactant that makes the least amount of product.
Completely consumed in a chemical reaction
NOTE:
- Also called "limiting reagent"
Excess Reactant (Reagent) - ANS The reactants that do not limit the amount of product (in
excess)
Usually greater than what is required to completely react with the limiting reactant.
Theoretical Yield - ANS The maximum possible amount (in grams) of product that can be made
in a chemical reaction based on the amount of limiting reactant.
TY = [Amount of product by limiting reactant]
x
[Molar mass of product]
Actual Yield - ANS The amount of product ACTUALLY produced by a chemical reaction.
Always equal to or less than the Theoretical Yield because a small mount of product is usually
lost to other reactions or foes not form during a reaction.
Percent Yield - ANS The percentage of the Theoretical Yield that was actually obtained.
Expressed as the ratio of the actual yield to the theoretical yield.
% Yield =
(Actual amount of product formed/
Maximum [possible] amount of product) x 100%
OR
(Actual Yield / Theoretical Yield) x 100%
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ALICE12. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78252 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now