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Chemistry Mid-term Review. Ch. 10, 11,13,14, and 15. Material You Should Review. From Last Year! Sig figs Types of Mixtures Exothermic vs. Endothermic Theories of the Structure of the Atom Emission Spectrum Orbitals Trends of the Periodic Table Valence electrons - PowerPoint PPT Presentation
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Chemistry Mid-term ReviewCh. 10, 11,13,14, and 15
Material You Should ReviewFrom Last Year!• Sig figs• Types of Mixtures• Exothermic vs. Endothermic• Theories of the Structure of the Atom• Emission Spectrum• Orbitals• Trends of the Periodic Table• Valence electrons• Ionic vs. Covalent Compounds• Compound Naming rules• Percent composition of a compound• Molecular Formulas vs. Structural Formulas• Molecular Structures• Moles/Molecules• Electronegativity
•All vocabulary words!!!
Material You Should ReviewFrom This Year!• Solubility/Properties of Solutions• Types of Solutions• Gas Laws/ Vapor Pressure• What are Acids/Bases/Conjugate Acids/Bases• Calculate pH and pOH/calculate [H+] and [OH-]• Titrations• Kinetic Energy• Phases change vocabulary• Kelvin scale• Molarity• Reading Phase Diagrams• Acid-Base Reactions
•All Vocabulary words!!!
CH. 10- Kinetic Energy• What is the Kinetic Theory of Matter?
1) Matter is made of particles2) Particles have Brownian motion (constant, rapid, and
random movement)3) Collisions of particles are perfectly elastic (complete transfer
of energy)
• What is the difference between a crystalline and amorphous solid?
Crystalline solids have a crystal lattice with repeating 3D patterns.
Amorphous have no lattice and random order• What is atmospheric pressure?
Pressure of gas molecules all objects in the Earth’s atmosphere experience. 1 atm = 760mmHg= 14.7 psi= 101.3 kPa
CH. 10- Kinetic Energy• Why do we use Kelvin when dealing with gases?
Kelvin directly relates the motion of the particles which produces the pressure of the gas.
• What is vapor pressure? How does it relate to the boiling point of a liquid?
Pressure produced by a vapor as a liquid changes to a gas. When vapor pressure and atmospheric pressure are equal, a liquid will boil.
• What is the heat of fusion? What is the heat of vaporization?Heat of fusion- amount of every needed to melt 1kg of substanceHeat of evaporation- amount of energy needed to vaporize
1kg of substance
CH. 10- Kinetic Energy• Label this diagram:
Condensation
Liquid
Gas
Melting point
Boiling Point
Melting
Evaporation
Solid
Freezing
Ch. 11- Gas Laws• Explain:• Boyle’s Law:
• Charles’ Law:
• Gay-Lussacs’ Law:
• Combined Gas Law:
• Ideal Gas Law:
• Avogadro’s Gas Principle:
• Dalton’s Law of Partial Pressures:
V1P1=V2P2; Volume and Pressure are inversely proportionate
V1/T1=V2/T2; Volume and Temperature are directly proportionate
P1/T1=P2/T2; Pressure and Temperature are directly proportionate
V1P1/T1= V2P2/T2
PV=nRT; connection between molar concentration of an ideal gas and its V, P, and T.
Ptotal=P1+P2+P3+…; total pressure is equal to sum of all none reactive gases
V1/n1=V2/n2; Moles of gas and the volume of the gas are directly proportionate
CH. 11- Gas Laws
V2 = P1V1/P2 = (0.66atm x 3.0L)/5.0 atm = 0.40 L
V2 = V1T2/T1= (10.0L x 423K)/298K = 14.2L
P2=P1T2/T1=(475.0 mmHg x 358K)/312K =546 mmHg
Ch. 11- Gas Laws
n=(75 atm)(14.0L)/(0.08206 L atm/ mol K)(295K)
n= 43 mol of NO2
V2= P1V1T2/P2T1= (1.77 atm x 2.00L x 324K)/(4.01 atm x 303K)V2= 0.944L
Ch. 13- Water and Solutions• What happens to water at 4oC and at temps lower than 4oC?
• Name 3 properties caused by H-bonds formed between water molecules
• What are the 3 types of solutions that can be produced with increasing solute concentration and solvent temperature?
At 4oC the water molecules are their most dense but as the temperature lowers the H-bonds form hexagonal shapes which forces water to expand as it freezes. This results in ice be less dense than water.
Adhesion- water molecules sticking to surfacesCohesion- water molecules sticking to each otherCapillary action- water moving up tubes against gravity Surface tension- water molecule resistant force on its surfaceHigh specific heat- water can absorb a lot of energy and releases it slowly
Unsaturated- still able to dissolve solute in the solventSaturated- maximum amount of solute within the solvent Supersaturated- raising the temperature allows for extra amounts of solute to dissolve in the solvent; crystalizes when cooled
Ch. 13- Water and Solutions
M= 0.6784 mol NaCl/ 4.5 L H2OM= 0.15 mol/L = 0.15 M
3 mol KBr
1 L H2O 1 mol KBr
119.0 g KBr 1 L H2O
1000 mL H2O= 349 g KBr
977.6 mL H2O
Ch. 13- Water and Solutions• What is the difference between a solution, a colloid, and a
suspension?
• What is the Tyndall effect?
• How can looking at the structure of a solute and solvent tell you if they will dissolve into each other?
Solution- solute completely dissolved; light pass throughColloid- solute completely dissolved; light scattersSuspension- solute separates over time; often reflects light
Light photons passing through a colloid collide with particles in the solution and scatter in random directions causing the colloid to glow
Using the “Like dissolves Like” rule, a non-polar molecules dissolve into non-polar substances and polar molecules dissolve into polar substances
Ch. 13- Water and Solutions• Explain how solutes effect the boiling and freezing points of a
solution
• What is an electrolyte?
Solutes dissolved in the solvent take up space between the solvent molecules. When the solution is boiling, the solute particles take up space on the surface of the solution which lowers the vapor pressure, so more energy (higher temp) is needed to boil the solution. When freezing the solutes take up space between the solvent molecules and prevent them from moving close together, so more energy (lower temp) must be removed to freeze the solution
A solution containing dissolved ions which will allow the passing of electrons through the medium. The more ions present the easier it is for the electricity to pass through the solution.
Ch. 14- Acids and Bases• What is ionization?
• How can you tell is a substance is an acid or base?
• SO3 and ZnO produce either an acid or a base when mixed with water. Which does each produce? What is the term for compounds that do this?
Breaking a covalent compound into ions. Happens with acids dissociating in solution
Acids produce hydronium ions (H+) in water while bases produce hydroxide ions (OH-) in water. B-L definition Acids give off H+ while bases take H+
SO3 (non-metal oxide) when mixed with water produces an acid (H2SO4) so it is an acidic anhydrideZnO (metal oxide) when mixed with water produces a base (ZnOH) so it is a basic anhydride
Ch. 14- Acids and Bases• What is the difference between a strong and weak acid/base?
• What is the equation for calculating pH? pOH?
• How do scientists monitor the change in pH when doing reactions?
Strong acids/bases dissociate completely in solution but weak acids/bases only dissociate a little
pH= -log[H+]pOH= -log[OH-]pH + pOH = 14
pH indicators are used to monitor pH changes Litmus paper can tell you if you have an acid or a base and liquid indicators that work in certain pH ranges will tell more specifically what your pH might be.
Ch. 14- Acids and Bases
• What is the [OH-] of a solution whose pOH = 10 ?
• What is the pH of a solution whose [H+] is 1.0 x 10-4 M?
• What is the [OH-] of a solution whose pH = 5 ?
• What is the pH of a 0.0001-M solution of NaOH?
[OH-] = 10-10 = 1.0x10-10 M
pH = -log[1.0 x10-4] = 4
pOH= 14- 5= 9; [OH-] = 10-9 = 1.0 x 10-9 M
0.0001 M NaOH = 0.0001 [OH-]pOH= -log [0.0001] = 4pH= 14-4 = 10
Ch. 15 Acid-Base Reactions• What are the reactants and products of a neutralization
reaction?
• What is the net iconic equation of reacting KOH and HCl?
• What acid-base reaction end with a slightly basic solution? Why?
Acid + Base A Salt + H2OHCl + NaOHNaCl + H2O
KOH + HCl KCl + H2O OH- + H+
H2O
Strong Base + Weak AcidWeak acid doesn’t dissociated enough to neutralize all the OH - ions produced by the base
Ch. 15 Acid-Base Reactions• Label the acid, base, and conjugate acid/base in these
reactions:H2O(l)+NH3(aq)NH4
+(aq)+OH-
(aq)
HCl(aq)+H2O(l)H3O+(aq)+Cl-
(aq)
• What is a buffer? How does it work?
Acid Base Conjugate BaseConjugate Acid
Acid Conjugate BaseConjugate Acid
Base
A solution of a weak acid or base and the salt of that same weak acid or base. Solution has compounds that will react with additional H+ and OH- ions so the pH of the solution changes slowly over time
Ch. 15 Acid-Base ReactionsAn acid base titration requires 29.88 mL of 1.17M NaOH to ‐neutralize 5.00 mL of an H2SO4 solution. Calculate the molarity of theH2SO4 solution.
2 NaOH (aq) + H2SO4 (aq) Na2SO4 (aq) + 2 H2O (l)
2MAVA=MBVB
MA= (29.88ml)(1.17M)/(2)(5.00ml)= 3.50 M H2SO4
A 20.00 mL sample of oxalic acid, H‐ 2C2O4, solution is titrated with
27.86 mL of 0.250 M KOH solution. Calculate the molarity of the H2C2O4 solution.
2 KOH (aq) + H2C2O4 (aq) K2C2O4 (aq) + 2 H2O (l)
2MAVA=MBVB
MA= (27.86ml)(0.250M)/(2)(20.00ml)= 0.174 M H2C2O4