Chemistry test 2
What are a few nonelectrolytes?
- neither acids or bases -->CH3OH methanol -->amides aka urea
The oxidation number on the carbon in CH₃OH is
-2
Short cut stuff
-50/50 dilutions cut the original concentration in half -10/100 dilutions reduce the original concentration by a tenth - or one dp to the left
How many moles of CH₃OH are there in 50.0 mL of 0.400 M CH₃OH?
0.02 mol
100.0 mL of a 0.500 M solution of KBr is diluted to 500.0 mL. What is the new concentration of the solution?
0.1 M
What is the concentration of a solution made with 0.150 moles of KOH in 400.0 mL of solution?
0.375 M
Two ways to make a solution
1. Measure out the solute, add it to a volumetric flask, add H2O and mix, and fill with solvent to the calibration mark 2. Dilution; add H2O to the original solution meniscus bottom to the mark is volume
Steps to combining empirical formula and mass percentage
1. Use 100.00g of compound (percent is grams) 2. Calculate the moles of each element 3. Determine mole's ratio
2 ways to calculate moles
1. grams to moles 2. volume to moles
What do we want to know in a oxidation-reduction reaction?
1.Who is oxidized? 2. Who is reduced? 3.Who is the oxidizing agent? 4. Who is the reducing agent? 5.How many electrons are lost and gained?
What are the three ways to write a acid-base and precipitation reaction?
1.molecular/formula unit 2.Complete/total ionic 3. Net ionic
How many grams of NO will be produced from 60.0 g of NO₂ reacted with excess water in the following chemical reaction? 3 NO₂ (g) + H₂O (l) → 2 HNO₃ (g) + NO (g)
13g
How many grams of precipitate are formed when 75 mL of 0.50 M FeCl₃ reacts with excess AgNO₃ in the following chemical reaction? FeCl₃ (aq) + 3 AgNO₃ (aq) → 3 AgCl (s) + Fe(NO₃)₃ (aq)
16.12 g
A particular protein sample is found to have one atom of iron in its chemical formula. If the mass percent of FE in the compound is 0.33% Fe, what is the molar mass of the protein?
16920.47377 g/mol
What volume (in mL) of 0.300 M HCl would be required to completely react with 5.00 g of Al in the following chemical reaction? 2 Al(s) + 6 HCl(aq) → 2 AlCl₃ (aq) + 3 H₂ (g)
1850 mL
What numbers belong in the blank spaces to fully balance the following reaction? __Fe (s) + __Cl₂ (g) → __FeCl₃ (s)
2,3,2
What volume of 0.200 M HCl is required to neutralize 50.0 mL of 0.800 M NaOH?
200mL
Complete the balances neutralization equation for the reaction below: KOH (aq) + H2SO4(aq)-->
2KOH(aq) + H2SO4(aq)--> 2H2O(l) + K2SO4 (aq)
Which one of the following represents the net ionic equation for the reaction of Ca(NO₃)₂ with Li₃PO₄?
3 Ca²⁺ (aq) + 2 PO₄³⁻ (aq) → Ca₃(PO₄)₂ (s)
Complete the balanced neutralization equation for the reaction below: NH₄OH(aq) + H₃PO₄(aq)-->
3 NH₄OH(aq) + H₃PO₄(aq) → (NH₄)₃PO₄(aq) + 3 H₂O(l)
If 50.0 g of CH₃OH (MM = 32.04 g/mol) are dissolved in 500.0 mL of solution, what is the concentration of CH₃OH in the solution?
3.12109862 M
To what volume would you need to dilute 20.0 mL of a 1.40 M solution of LiCN to make a 0.0900 M solution of LiCN?
311 mL
The oxidation number on the nitrogen in NO₃⁻ is
5
If 33.6 g of NO and 26.9 g of O₂ react together, how many grams of NO₂ can be formed via the reaction below? 2 NO (g) + O₂ (g) → 2 NO₂ (g)
51.5 g
When butanol (C₄H₉OH) is burned in oxygen, CO₂ and H₂O are the products. What is the coefficient in front of the O₂ in the balanced equation (using only whole numbers and the lowest whole number ratio)?
6
How many grams of nitric acid, HNO₃, are required to neutralize (completely react with) 4.30 g of Ca(OH)2 according to the acid-base reaction: 2 HNO₃(aq) + Ca(OH)₂(aq) → H₂O(l) + Ca(NO₃)₂(aq)
7.20 g HNO3
What is the mass percentage of C in morphine, C17H19NO3?
71.5%
What is the mass percentage of O in CO2?
72.7%
What is the mass percentage of C in CH3CH3?
79.85%
One of the commercial uses of sulfuric acid is the production of calcium sulfate and phosphoric acid. If 19.9 g of Ca₃(PO₄)₂ reacts with 54.3 g of H₂SO₄, what is the percent yield if 10.9 g of H₃PO₄ is formed via the UNBALANCED equation below? Ca₃(PO₄)₂ (s) + H₂SO₄ (aq) → H₃PO₄ (aq) + CaSO₄ (aq)
86.7%
How many grams of carbon dioxide would be required to react with 10.0 g of LiOH in the following chemical reaction? 2 LiOH(s) + CO₂ (g) → Li₂CO₃ (s) + H₂O (l)
9.2 g
In the following chemical reaction, which element is the reducing agent? 2 Ag(s) + 2Cl⁻(aq) + 2 H₂O(l) → 2 AgCl(s) + H₂(g) + 2 OH⁻(aq)
Ag
Which one of the following represents the net ionic equation for the reaction of AgNO₃ and LiBr?
Ag⁺ (aq) + Br⁻ (aq) → AgBr (s)
Balance the following chemical reaction: Al₂(SO₄)₃ (aq) + K₃PO₄ (aq) → AlPO₄ (s) + K₂SO₄ (aq)
Al₂(SO₄)₃ (aq) + 2 K₃PO₄ (aq) → 2 AlPO₄ (s) + 3 K₂SO₄ (aq
In the following reaction, which element in what species is oxidized? C₂H₄ (g) + 3 O₂ (g) → 2 CO₂ (g) + 2 H₂O (g)
C in C₂H₄
Glucose is an important biological molecule with the molecular formula C6H12O6. What is its empirical formula? a. CHO b. CH2O c.C2HO2 d. C6H12O6
CH2O
Weak acids
CH3COOH
Weak bases
CH3NH2
In which one of the following molecules does chlorine have the highest oxidation number?
ClO4-
Which one of the following represents the molecular equation for the reaction of HNO₃ with CsOH?
CsOH (aq) + HNO₃ (aq) → H₂O (l) + CsNO₃ (aq)
The precipitate formed when Fe(NO₃)₃ is mixed with KOH is
Fe(OH)₃
Fe 2 O3
Ferric Oxide or Iron (III) oxide
In the following reaction, which element in what species is reduced? Zn (s) + 2 HCl (aq) → ZnCl₂ (aq) + H₂ (g)
H in HCl
Strong Acids
HCl, HBr, HI, HNO3, H2SO4, HClO4
Which one of the following is NOT a strong electrolyte?
HNO₂
Strong Bases
LiOH, NaOH, KOH, Ba(OH)2, CsOH, RbOH
Dilution Equation
M1V1=M2V2 M- molarity V-volume 1- concentrated solution 2- dilute solution
Sparingly soluble ionic compounds
MgOH2
The ions formed when MgI₂ dissociates in water are
Mg²⁺ and I⁻
Example of writing an total/complete ionic equation
Na(+)aq + Cl(-)aq+Ag(+)aq+ NO3(-)aq---> AgCl(s)+ Na(+)aq+NO3(-)aq
Which one of the following would form a precipitate when mixed with aqueous Ba(NO₃)₂?
Na2SO4
Example of precipitation
NaCl(aq)+AgNO3(aq)---> AgCl(s)+NaNO3(aq)
In the reaction between FeCl₃ and NaOH, the spectator ions are
Na⁺ and Cl⁻
The precipitate formed when Ni(NO₃)₂ is mixed with Li₂S is
NiS
The ions formed when CH₃OH dissociates in water are
No ions form, as CH₃OH does not dissociate
way to remember oxidation-reduction reaction
OIL RIG Oxidation Loss AND Reduction Gain
Gas evolution reaction
a reaction in which two aqueous solutions are mixed and a gas forms, resulting in bubbling or fizzing
Acid-Base Reactions
acid+base-->salt+water -aka neutralization reaction
Molecular Formula
actual number of each written out
percent yield
actual yield/theoretical yield x 100
Law of Conservation of Mass
amount of matter in the universe is constant - no creating or destroying -only rearranging
Assigning oxidation numbers does what?
answer the 5 question
oxidation-reduction reaction
any chemical change in which one species is oxidized (loses electrons) and another species is reduced (gains electrons); also called redox reaction
A compound that contains only carbon, hydrogen, and oxygen is 58.8% C and 9.87% H by mass. What is the empirical formula of this substance? a. C2x5H5O b.C5H10O2 c.C6H4O d.C4H8O2 e.C5H5O2
b.C5H10O2
Weak electrolytes are made of
both ions and molecules and are dim
The empirical formula of a covalent compound is CH2. Which of the following is NOT a possible chemical formula for this compound? a.C5H10 b.C7H14 c.C6H10 d.C4H8 e.C3H6
c. C6H10
Molarity
concentration unit -to talk about how much solute in a solution
An iron-containing compounds is 20.1 % Fe, 11.5% S, 63.3% O, and 5.1% H. What is the empirical formula for this compound? a. Fe3SO19H25 b.Fe15S9O50H c.FeS2O22H28 d.FeSO11H14
d.FeSO11H14
net ionic equation
does NOT include spectator ions in the example: Ag+aq and Cl-aq
limiting reactancts
gets used up first, and limit the amount of product that can form (determines theoretical yield)
way to remember grams to moles to moles to grams?
ground mole or gramolgra
Oxidizing agent
helps with oxidation by being reduced -takes agents to let something be oxidized
Reducing agent
helps with reduction by being oxidized
Another Empirical Formula Calculation
in notes - If it is not an integer but it is needed, use numbers between 2-9 and use the "flip" function of your calculator (X^-1) - continue till finding the exact decimal needed - once finding, times by the integer to gain new integer (make sure to do this to all other Mole Ratios
Strong electrolytes are made of
ions and are bright
Spectator ions
ions that do not participate in a reaction, they only watch in the example they are Na+aq and NO3-aq
Solutions
is a homogenous mixture of a solute and solvent
excess reactancts
left overs after the reaction is complete
Oxidation
loss of electrons; the oxidation number increases for the element, going from reactant to product
Formula mass
mass of all (carbon, hydrogen or oxygen) in a acid/ mass of acid X 100
Theoretical yield
maximum amount of product obtainable
Nonelectrolytes are made of
molecules and have no illumination
Balanced chemical equation
need the same amount on each side for each element
What are Non-electrolytes?
neutral compounds
What are non-electrolytes made out of?
no ions and doesnt make ions in the solutions -almost zero
In the following chemical reaction, which element is the oxidizing agent? CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g)
o
What can indicate precipitation?
ppt
Empirical Formula
simplest, whole number ratio for a molecule
how do you write soluble/insoluble equations in an total/complete ionic equation?
soluble compounds are written "apart" insoluble compounds stay together
3 types of electrolytes
strong weak non
Stoichiometry
study of the mass-mole relationship in a chemical reaction
To determine mole's ratio?
take the smallest mole and divide the rest
Reduction
the gaining of electrons; the reduction number decreases for the element. going form reactant to product
Solute
the substance being dissolved in a solution (minor component)
Solvent
the substance doing the dissolving (major component)
electrolytes
these substances when added to H2O, produce ions and make a solution that conducts electricity
