Warm Up Predict the products of the following 2 reactions: 1.NaCl + MgF2 → ? + ? 2.Calcium oxide and barium sulfide → ? and ?

Take 1

What to do??? Make sure you have a tracking sheet (all versions are the same) Get calculators from the bin. Return them when finished Complete ALL parts of tracking sheet Raise hand to ask questions You may track a classmate’s for extra credit…make sure to put their name on it

Chemical Reactions Situation where atoms rearrange to make new substances.

Reactants BEFORE What you start with. What reacts or rearranges

Reactants Products BEFORE What you start with. What reacts or rearranges AFTER What you end with. What is produced.

Double Replacement How to predict products? –Just switch partners –Cations (positive ions) still come first in the formula –Anions (negative ions) still come last in the formula –Polyatomic ions move as a unit –Example?

Practice Double Replacement (aka partner switch!) What forms from: 1.Calcium sulfide and magnesium oxide 2.Potassium chloride and hydrogen carbonate 3.Sodium hydroxide and lithium bromide

Practice Double Replacement (aka partner switch!) What forms from: 1.NaCl and LiF 2.CaO and MgS 3.MgCl 2 and CaI 2 4.CaF 2 and Li 2 O

Kris Kross Method! Ca 3 As 2 Ca 2+ As 3-

Write down the stable ions and cross the oxidation numbers (charges) to make them subscripts Na 1+ Cl 1- NaCl Pb 4+ O 2- Pb 2 O 4

Write down the stable ions and cross the oxidation numbers (charges) to make them subscripts Na 1+ Cl 1- NaCl Pb 4+ O 2- Pb 2 O 4

Write down the stable ions and cross the oxidation numbers (charges) to make them subscripts Na 1+ Cl 1- NaCl Pb 4+ O 2- Pb 2 O 4

Extra Rules DON’T cross signs (+ or -) DON’T cross 1’s If the numbers are the same, DON’T cross them (if both are 3’s, don’t cross them) Reduce final subscripts if able to

Ionic Compounds K F Ba N Ga O Ca Cl K Si Group Charge

Ionic Compounds K + F - Ba N Ga O Ca Cl K Si Group Charge

Ionic Compounds KF Ba N Ga O Ca Cl K Si Group Charge

Ionic Compounds KF Ba 2+ N 3- Ga O Ca Cl K Si Group Charge

Ionic Compounds KF Ba 3 N 2 Ga O Ca Cl K Si Group Charge

Ionic Compounds KF Ba 3 N 2 Ga 3+ O 2- Ca Cl K Si Group Charge

Ionic Compounds KF Ba 3 N 2 Ga 2 O 3 Ca Cl K Si Group Charge

Ionic Compounds KF Ba 3 N 2 Ga 2 O 3 Ca 2+ Cl - K Si Group Charge

Ionic compounds KF Ba 3 N 2 Ga 2 O 3 CaCl 2 K Si Group Charge

Ionic compounds KF Ba 3 N 2 Ga 2 O 3 CaCl 2 K + Si 4- Group Charge

Balancing Chemical Reactions KF Ba 3 N 2 Ga 2 O 3 CaCl 2 K 4 Si Group Charge

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Matter is Conserved! If mass is never created/destroyed, and it can be measured, then: Key Point 3: Total mass of products = Total mass of reactants

Now Let’s Apply: A student takes 30g of BaCl 2 and reacts it with 25 g of LiOH. BaCl 2 + LiOH  LiCl + Ba(OH) 2 What is the total mass of the products formed?

Now Let’s Apply: A student takes 30g of BaCl 2 and reacts it with 25 g of LiOH. BaCl 2 + LiOH  LiCl + Ba(OH) 2 What is the total mass of the products formed? 55g.

Practice, Practice, Practice 45g of K 3 PO 4 are combined with 25g of NaOH. What is the total mass of products? 35g of MgSO 4 are combined with 30g of KCl What is the total mass of products?

Practice, Practice, Practice 45g of K 3 PO 4 are combined with 25g of NaOH. What is the total mass of products? 70g 35g of MgSO 4 are combined with 30g of KCl What is the total mass of products?

Practice, Practice, Practice 45g of K 3 PO 4 are combined with 25g of NaOH. What is the total mass of products? 70g 35g of MgSO 4 are combined with 30g of KCl What is the total mass of products? 65g

Practice, Practice, Practice 70g of BaCl combines with 50g of NaOH What is the total mass of products? 253.4g of NaOH combines with 123.4g of LiCl What is the total mass of products?

Practice, Practice, Practice 70g of BaCl combines with 50g of NaOH What is the total mass of products? 120g 253.4g of NaOH combines with 123.4g of LiCl What is the total mass of products?

Practice, Practice, Practice 70g of BaCl combines with 50g of NaOH What is the total mass of products? 120g 253.4g of NaOH combines with 123.4g of LiCl What is the total mass of products? 376.8g

Practice, Practice, Practice 70g of BaCl combines with 50g of NaOH and forms 60 g of BaOH. What is the mass of the NaCl that forms? 250g of NaOH combines with 125g of LiCl and forms 100 g of NaCl. What is the mass of the LiOH that forms?

Practice, Practice, Practice 70g of BaCl combines with 50g of NaOH and forms 40 g of BaOH. What is the mass of the NaCl that forms? 80g 250g of NaOH combines with 150g of LiCl and forms 100 g of NaCl. What is the mass of the LiOH that forms? 300g

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Balancing equations RULES! When balancing equations, Never, Never, NEVER change subscripts, only coefficients!

But Ms. Hughes… What is a coefficient? GOOD QUESTION!

Coefficient A coefficient is a whole number in front of the compound, never in the middle! You multiply the coefficient to all the subscripts in the compound 2AlCl 3

Do you get it? 3AlCl 3 How many atoms of each element do they have? ? Aluminum’s ? Chlorine’s

Practice 2AlCl 3 4H 2 O 6H 2 O 2 5KCl 2Be 3 S 2

Balancing Chemical Reactions H 2 + O 2  H 2 O __H__ __O__ Write down elements.

Balancing Chemical Reactions H 2 + O 2  H 2 O __H__ __O__ How many are there?

Balancing Chemical Reactions H 2 + O 2  H 2 O _2_H_2_ __O__ How many are there?

Balancing Chemical Reactions H 2 + O 2  H 2 O _2_H_2_ _2_O_1_ How many are there?

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Mg(s) + O 2 (g)  2MgO

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Na(s) + O 2 (g)  Na 2 O(s)

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. 2Al(s) + Cl 2 (g)  Al 2 Cl 3 (s)

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Br 2 + O 2  2Br 2 O

Balancing Equations 1) Determine number of atoms for each element. 2) Pick an element that is not equal on both sides of the equation. 3) Add a coefficient in front of the formula with that element and adjust your counts. 4) Continue adding coefficients to get the same number of atoms of each element on each side.

Balancing Chemical Reactions H 2 + O 2  H 2 O _2_H_2_ _2_O_1_ How many are there?

Balancing Chemical Reactions Try These: N 2 + H 2  NH 3 P 4 O 10 + H 2 O  H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

Balancing Chemical Reactions Try These: N 2 + 3H 2  2NH 3 P 4 O 10 + H 2 O  H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

Balancing with some hot sauce… When balancing equations with polyatomic ions, keeping them together can make it easier! What if you have some polyatomic ions? WHAAAAAAAAT will you do??

Work it out… H 3 PO 4 + ____ KOH  ____ K 3 PO 4 + ____ H 2 O Which polyatomics are we using? –PO 4 – phosphate –OH – hydroxide Where is the OH on the other side? –It’s okay – rewrite H 2 O as HOH –Trust me!

Balancing Chemical Reactions Try These: N 2 + 3H 2  2NH 3 P 4 O H 2 O  4H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

Balancing Chemical Reactions Try These: N 2 + 3H 2  2NH 3 P 4 O H 2 O  4H 3 PO 4 Ca 3 P 2 + 6H 2 O  3Ca(OH) 2 + 2PH 3

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Warm Up 1.Does breaking a bond absorb or release energy? 2.Does forming a bond absorb or release energy? 3.How is an exothermic reaction different from an endothermic reaction?

Why does the temperature change?!? Key Point #1: Breaking a bond requires energy. Forming new bonds releases energy. Unit for energy: kilojoules (kJ)

Endothermic = energy ABSORBED energy goes IN

Exothermic = energy RELEASED energy EXITS

Endo or Exo??? 1. 2 HCl kJ  H 2 + Cl NH O 2  4 NO + 6 H 2 O kJ 3. Cu + Cl 2  CuCl kJ 4. H 2 O + C kJ  CO 2 + 2H 2

Some Questions to ponder The combustion of the hydrocarbon glucose (C 6 H 12 O 6 ) produces carbon dioxide, water, and releases 2830 kJ. Exo or Endo???

Some Questions to ponder After absorbing 66.4 kJ of energy, 1 mole of nitrogen gas and 2 moles of oxygen gas react to form 2 moles of nitrogen monoxide. Exo or Endo???

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Remember to look up the names of polyatomic ions Gases like oxygen, etc are O 2 –“diatomic” + means “and” → means “yield”

States of Matter Products and reactants in chemical reactions are present in different states Solid (s) Liquid (l) Gas (g) Aqueous (aq)- dissolved in water Precipitate (ppt)- solid product of a reaction

Practice- what is formula equation? Solid magnesium and aqueous Aluminum Chloride react to form an Aluminum precipitate and aqueous Magnesium Chloride

Practice- what is the formula equation? aqueous sodium chloride reacts with aqueous lead (II) nitrate to yield a lead (II) chloride precipitate and aqueous sodium nitrate

Solid Potassium metal and chlorine gas combine to form aqueous potassium chloride.

Aluminum and liquid hydrochloric acid (HCl) react to form Solid aluminum chloride and hydrogen gas.

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Mg(s) + O 2 (g)  2MgO

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Na(s) + O 2 (g)  Na 2 O(s)

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. 2Al(s) + Cl 2 (g)  Al 2 Cl 3 (s)

Is this chemical equation balanced? Defend you answer and how it relates to the Law of Conservation of Mass. Br 2 + O 2  2Br 2 O

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Warm Up 1.When pressure increases, what happens to volume? 2.When temperature increases, what happens to volume?

Conclusions Pay attention Remember: CAUSE → EFFECT Lines intersecting on a graph means the values are equal at that point It’s all about relationships!

Conclusions Incubation Temperature of Turtle Eggs Versus Sex of Hatchlings Four groups of 25 eggs TemperatureNumber of Males Number of Females Eggs not hatched Group Group Group Group

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Gases Particles are: –Spread apart –In constant motion –Very small –Exert force on each other when collide –Exert force on container when collide –Which is the gas?

Volume Volume measures how much space matter takes up. The units of Volume are Liters (L) –1 L = 1000 mL

Pressure Pressure describes how much force is applied over an area. –The more force, the more pressure. –The more area, the less pressure Why doesn’t this person have a lot of holes in their body?

Gas Pressure Gas Pressure is a measure of how much force the gas molecules hit the container with. –If the gas molecules hit the container harder, what will happen to the pressure? Answer in complete sentences

Units of Pressure Pressure is measured in many different units. –Atmospheres (atm) –Kilopascals (kPa) –Millimeters of Mercury (mm Hg) –Torr (torr) 1 atm = kPa = 760 mm Hg = 760 torr

Pressure and Volume Recall: –Pressure is related to the force on the gas molecules in the container –Volume is how much space the gas takes up Imagine a balloon. –If the pressure on the gas molecules increases what do you think will happen to the volume the gas molecules take up? Explain your answer on the sheet in complete sentences

Boyle’s Law Boyle’s Law relates gas pressure and gas volume Equation: Initial PressureInitial VolumeFinal Pressure Final Volume *You can use any units, as long as they are on the same on each side

Temperature Temperature is a measure of how fast the molecules in a substance are moving. –The faster they move, the higher the temperature Temperature is measured in: –Degrees Fahrenheit (°F) –Degrees Celsius (°C) –Kelvin (K)

Charles’ Law Charles’ Law relates the temperature of a gas to the volume of a gas. The units for T must be Kelvin (K). –What could happen if the temperature was in C or F? The units for volume can change. Initial Volume Initial Temperature Final Temperature Final Volume

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Significant figures A way of keeping track of the precision of a measurement

Significant figures All measured digits + 1 guessed digit

What’s the measurement? Graduated cylinder- measure from the bottom of the curve

What’s the measurement? Triple beam balance- add three levels together

How many sig figs? Graduated cylinder- measure from the bottom of the curve

How many sig figs? Triple beam balance- add three levels together

How many sig figures?

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Warm Up 1.What is the purpose of multiple trials? 2.Which of the following conducts electricity in water: NaCl or C2H3O2

Multiple Trials Doing an experiment multiple times or having multiple subjects Necessary to reduce error by taking the average Need a trial that has the control group (original form)

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With addition of solute Boiling point increases Freezing point decreases

Why? Explain, in complete sentences, why people add salt to water to make the pasta cook faster. Explain, in complete sentences, why salt is added to roads when it snows.

BP and FP Change Equation Change in temperature constant molality Number of dissolved particles k b for water is 0.51 °C/m k f for water is °C/m

An Example What is the boiling point of a 0.75 m MgF 2 if water is the solvent?

Practice Questions Which of the following will increase the boiling point of solvent the most? –1 m NaCl –1 m C 12 H 22 O 11 –1 m CaCl 2 –1 m Al 2 O 3 –1 m MgO What is the freezing point of a salt (NaCl) water solution with a molality of 3 m? Question #1Question #2

More Practice What is the molarity of a solution with 2.0 moles of CaCl 2 in 4 L of H 2 O? What is the molality of a solution with 4.0 moles of CaCl 2 in 6 L of H 2 O? What is the boiling point of a solution with 4 m CaCl 2 in water? Practice Quietly by yourself. Raise you hand if you have a question

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Conductivity When ions are dissolved in water, they can conduct electricity –Because they can move charges in the liquid Why can’t ionic compounds conduct electricity while they are solids? Why can’t covalent compounds dissolved in water conduct electricity?

Review: ionic compound A METAL + A NONMETAL

Why do some ionic compounds conduct better? More ions per volume of solution (concentration) means more charge is carried (better conduction) Ionic compounds that create more ions (higher concentration) when dissolved conduct electricity better

REMEMBER: Dissolution Dissolution is when an ionic compound dissolved into ions in a polar solvent. –How many ion (not particles) will the following compounds make? NaCl2 CaCl 2 3 CH 3 OH none

Practice Problems Which of the following will conduct electricity? –Pure water –Salt water –A pile of salt –Sugar water –A pile of sugar In complete sentences, explain why gatorade and powerade can conduct electricity. Question #1Question #2

Practice NaCl H2O H2O with dissolved ions C2H6O3 MgCl2 Strong electrolyte Weak electrolyte Solutions with high concentration of dissolved ions

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