A 1000 watt iron produces 1000 joules (1 kilojoule) of energy per second. How many kilocalories of energy is generated in one hour? (1 calorie=4.184 joules)

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Study guide for Part 1 of Final Exam

• A 1000 watt iron produces 1000 joules (1
  kilojoule) of energy per second. How many
  kilocalories of energy is generated in one hour?
  (1 calorie4.184 joules)
• 1000 joules1 cal kilo 60 sec60 min 860
  kcal sec 4.184 J 1000 1 min 1 hr
• How many atoms of chlorine is in dinitrogen
  tetrachloride?
• What volume of oil will have the same mass at 51
  mL of mercury? (oil density 0.90 g/mL, mercury
  density13.6 g/mL)
• 51 mL 13.6 g 693.6 g 693.6 g 1 mL 771mL
  mL 0.90g

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• Know acid names and formulas Hydrochloric acid,
  Nitric acid, Nitrous acid, Sulfuric acid,
  sulfurous acid, Phosphoric acid
• Physical change versus chemical change
• Physical change is a change from solid to liquid
  or a liquid to gas.
• A chemical change is coming apart or combining
  with other elements or compounds. Burning,
  rusting, decomposing, reacting with other
  compounds are examples.

3

• Precision versus accuracy
• If your measurements are close to each other, you
  have precision. If they match a known or
  expected value, then you have accuracy.
• Know pure element, compound, and mixture.
• An element is made of just one kind of atom. O2
  is and element even though there are two of them
  together.
• A compound is two or more elements combined.
  Visually you would see two different atoms
  (spheres) joined.
• A mixture are two or more compounds mixed but
  not bonded together. Visually, you would see
  more than one kind of atom or molecule separate
  from each other.

O
O
C
O
C
O
N
N
4

• Know charge on polyatomic ions like chlorates,
  sulfates, carbonates, phosphates
• Know a precipitation reaction
• NaCl(aq) AgNO3(aq) ? AgCl(s) NaNO3(aq)

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• What is produced when alkali metals or alkaline
  earth metals are placed in water.
• Na H2O ? or write
• 2Na(s) 2HOH(l) ? 2NaOH(aq) H2(g)
• What is difference between total ionic equation
  and net ionic equation?
• Top is total ionic, bottom is net ionic
• Na(aq) Cl-(aq) Ag(aq) NO3-(aq) ? AgCl(s)
  Na(aq) NO3-(aq)
• Cl-(aq) Ag(aq) ? AgCl(s)

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• Figuring oxidation number of metals combined with
  non-metals such as 6A, 7A non-metals. CuS,
  TiF4, TiO2, MnO4-.
• Always start with the oxidation number of the
  non-metal. Sulfur and oxygen are -2.
• Copper is 2, Ti is 4 for both, and Mn is 7.
• What would neutralize acids? Hydroxides (OH-) or
  carbonates (CO32-).
• Solubility rules.
• Sulfates are soluble except for barium and lead.
  Chlorides, bromides, and fluorides are soluble
  except for silver, lead, and mercury.

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• Given moles of one compound in a reaction, give
  moles of the others.
• 2KClO3 ? 2KCl 3O2
• 0.245 moles O2 2 mol KClO3 0.163 moles KClO3
  3 mol O2
• Discern excess or insufficient quantities in a
  reaction.
• 2Al 3Cl2 ? 2AlCl3 (57 g Al 200g of Cl),
  which reactant has an excess and how much?
• 54 g Al 1 mol 2.1 mol Al 27 g
• 200 g Cl1 mol 5.6 mol Cl or 2.8 mole Cl2
  35.6 g
• 2.1 mol Al 3 mol Cl2 3.15 mol Cl2
  2 mole Al
• 2.8 mol Cl2 2 mol Al 1.87 mol Al
  3 mole Cl2
• 2.8 moles of Cl2 can is only enough to react with
  1.87 mol Al. Since there are 2.1 moles of Al,
  there is 0.23 (2.1-1.87) moles of Al in excess.
  For grams thats 0.23 mol x 27g/mole 6.2 grams.

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• Figure yield
• 12 grams of calcium chloride is reacted with an
  excess of sodium carbonate to make 9.5 grams of
  calcium carbonate. What was the yield?
• CaCl2(aq) Na2CO3(aq)? CaCO3(s) NaCl(aq)
• 12 g CaCl2 1 mol 0.11 mol CaCl2
  111 g
• 9.5 g CaCO3 1 mol 0.095 mol CaCO3
  100 g
• 0.11 mol CaCl2 should produce 0.11 mole of CaCO3
  however, it only produced 0.095 moles. So the
  fraction of what it did produced over what it
  should have is 0.095/0.11 86 yield.
• Equipment to make up a specific molar solution.
• Moles per Liter. To find moles we need a
  balance. To measure liter accurately, we use a
  buret or a volumetric flask. But to make molar
  concentratons, a compound is placed in some water
  and the level brought up to one liter. So a
  volumetric flask is the best.
• Evidence of reactions (heat, precipitate, gas,
  color change)

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• Percent mass of one element in a compound
• KMnO4, --- What is percent mass of manganese?
• K 39 g/mol, KMnO4 158 g/mol. 39/158
  0.25 or 25
• Balance a combustion reaction.
• C5H8O3 O2 ? CO2 H2O
• Balance carbons with CO2 first, and hydrogen with
  water. Do O2 last.
• Basic dilution problem.
• Conc x Vol Conc x Vol
• Concentrated Diluted
• How many mL of 2.5 molar solution of HCl is
  needed to make up 350 mL of 0.1M HCl?
• Concentrated Diluted
• 2.5 M x ?mL 0.1M x 350 mL
• Divide both sides by 2.5M to have mL
  0.1Mx350mL/2.5M
• ?mL 14 mL

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• Moles of one element in a compound, knowing the
  compounds mass and formula.
• 24 grams Na2SO4, how many moles of sulfur is
  there?
• 24 g Na2SO4 1 mol 0.169 mol Na2SO4
  142 g
• Since theres one sulfur in sodium sulfate, then
  the moles of sulfur is the same as the sodium
  sulfate.
• Knowing energetic light has shorter wavelength
  and higher frequency. Radio waves, infrared,
  visible light, ultraviolet, x-rays, gamma rays.
  Which has the shortest wavelength, which has
  highest frequency? Gammas rays are the shortest
  wavelength and the highest freqeuncy.

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• Heat of formation page 244, 242
• Bond energies page 341 for table, page 349 for
  problem.
• Electron configuration page 301, 302