Was the Wicked Witch a good chemistry student? Did she correctly and scientifically describe her...
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Transcript of Was the Wicked Witch a good chemistry student? Did she correctly and scientifically describe her...
Was the Wicked Witch a good chemistry student?
Did she correctly and scientifically describe
her demise?
1
Question of the Day
Day 3 2-25
Electrolytes and Nonelectrolytes•Your cells use electrolytes, such as sodium and potassium ions, to carry electrical impulses across themselves and to other cells.
• An electrolyte imbalance can occur if you become dehydrated.
• When you exercise, you can lose water and electrolytes from your body through perspiration.
A. Metathesis reactions can also be called _______ ______________ reactions.
B.The mixing of 2 solutions will result in a chemical reaction if _____ are _________ from the solution.
double replacement
ions removed
4
Metathesis (Exchange) Reactions
• Metathesis comes from a Greek word that means “to transpose.”
AgNO3 (aq) + KCl (aq) AgCl (s) + KNO3 (aq)
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Metathesis (Exchange) Reactions
• Metathesis comes from a Greek word that means “to transpose.”
• It appears the ions in the reactant compounds exchange, or transpose, ions.
AgNO3 (aq) + KCl (aq) AgCl (s) + KNO3 (aq)
6
Solution Chemistry
• It is helpful to pay attention to exactly what species are present in a reaction mixture (i.e., solid, liquid, gas, aqueous solution).
• If we are to understand reactivity, we must be aware of just what is changing during the course of a reaction.
7
Ions can be removed from solution by any of 3 processes:
1. The formation of an __________ solid, known as a _____________
2. The formation of either a weak
____________ or a ________________
3. The formation of a ____ that bubbles
out of the solution
insolubleprecipitate
electrolyte nonelectrolyte
gas
8
Precipitation Reactions
When one mixes ions that form compounds that are insoluble (as could be predicted by the solubility guidelines), a precipitate is formed.
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C. ExamplesWrite the molecular, complete, and net ionic equations
for these reactions that occur in water.
1. Magnesium nitrate and sodium hydroxide
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C. ExamplesWrite the molecular, complete, and net ionic equations for
these reactions that occur in water.
2. Magnesium hydroxide and hydrochloric acid
11
1. What volume of 10 M HCl must be diluted to prepare 500 mL of 1 M HCl?
2. Barium hydroxide has a low solubility, but is considered a strong electrolyte. Explain how this is possible.
15
Question of the Day
Day 4 2-26
C. ExamplesWrite the molecular, complete, and net ionic equations
for these reactions that occur in water.
3. Chromium(II) acetate and nitric acid
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C. ExamplesWrite the molecular, complete, and net ionic equations
for these reactions that occur in water.
4. Barium nitrate and sulfuric acid
19
• Which dissolves faster sugar cubes or granulated sugar?• Why the stirring?• Sugar dissolves faster in hot / iced tea?
Solution Formation
Solution FormationThe compositions of the solvent and the solute determine whether or not a substance will dissolve.
•Factors that affect how fast a substance
dissolves include:
• Agitation
• Temperature
• Particle size of the solute
Like Dissolves Like
Solution Formation• AgitationAgitation (stirring or shaking) affects only the rate at which a solid solute dissolves.• It does not influence the
amount of solute that will dissolve.
• Agitation increases the rate of dissolving
Solution Formation
•Higher temperatures lead to an increased rate of dissolving.
Temperature
•At higher temperatures, the kinetic energy of molecules is greater than at lower temperatures, so the molecules move (and mix) faster.
Solution Formation• Particle Size of the Solute
Smaller particles expose a greater surface area and so increase rate of dissolving.• The more surface area of
the solute that is exposed, the faster the rate of dissolving.
•Which of the following will not speed up the rate at which a solid solute dissolves?
• A. Increasing the temperature
• B. Stirring the mixture
• C. Crushing the solute
• D. Decreasing the temperature
34
Quick DrawMolarity
Net ionic equation
Solute
Dissociating
Diprotic acids
Spectator ions
VcMc=VdMd
electrolyte
Strong acids
mols/L
salts
Weak base
QUICK TALKNH3
Disperse
Strong base
Hydrogen bonding
Solute
Molecular equation
Molarity
Weak acid
Solvent
Tincture
VcMc = VdMd
Monoprotic