Chem Unit 6 Things
--> symbol means ___ and is used to ____
"Yields," separate reactants from products
What is the Activity Series of Metals?
(this sheet will be on the useful info sheet) - Single-replacement reactions depend on an activity series. - The metal activity series lists metals in order of reactivity and allows us to predict if one metal will replace another. - A reactive metal will replace any metal listed below it (less reactive) in the activity series. - If a metal is listed below another metal, it will not replace the other metal. Examples: - Iron will displace copper from a copper compound in solution. (iron is more reactive than what its trying to replace so the reaction will occur) - Fe(s) +2CuNO3(aq) --> 2Cu(s)+ Fe(NO3)2(aq) - Magnesium does not displace lithium from aqueous solutions of their compounds. (magnesium is not more reactive than lithium so this wont work) - Mg(s) + LiNO3(aq) --> no reaction
What is a synthesis reaction?
- A reaction that occurs between two or more substances to form ONE new compound. - A + B → AB - Na + Cl2 --> NaCl · Examples: - 2H2(g) + O2(g) → 2H2O(l) - Element + Element Compound - CaO(s) + H2O(l) →Ca(OH)2(aq) - Compound + Compound Compound
What is a decomposition reaction?
- A single compound undergoes a reaction that produces two or more simpler substances (compounds or elements). - AB → A + B Examples: - 2H2O(l) →2H2(g) + O2(g) - 2KClO3(aq) → 2KCl(aq) + 3O2(g)
binary compound breaking down into two elements examples:
- CaBr2(s) --> Ca(s) + Br2(l) - 2SO3(g) --> 2S(s) + 3O2(g) - 2Ag2O(s) --> 4Ag(s) + O2(g)
examples of metal oxide + water synthesis reactions
- CaO(s) + H2O(l) → Ca(OH)2(aq) - Cr2O3(s) + 3H2O(l) → 2Cr(OH)3(aq)
What is a combustion reaction?
- Combustion reactions are used to produce heat and light - A hydrocarbon (CxHy) ALWAYS combines with oxygen, releasing a large amount of heat and light, to ALWAYS form carbon dioxide and water. Example: C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)
What is a single replacement reaction?
- Compounds + Element --> C + E (original lonely element switches with an element) _________________ - One element replaces a similar element in a reaction. Cationic - a positive (metal) ion replaces a positive ion - A + BX → AX + B _________________ - Anionic- a negative (nonmetal) ion replaces a negative ion - Y + BX → BY + X
Synthesis Reactions
- In a synthesis reaction, two or more simple substances combine to form a more complex substance. - Two or more reactants come together to form one product.
Metal + compound --> compound + metal examples?
- Mg(s) + 2AgNO3(aq) --> Mg(NO3)2(aq) + 2Ag(s) - Co(s) [Since cobalt is close to iron and nickel, just put it near there] + PbSO4(aq) --> CoSO4(aq) + Pb(s) This means cobalt is more reactive than lead
What are the two types of Synthesis Reactions?
- Two pure elements combine to form one compound. (watch out for ionics) - Metal oxide and water form a metal hydroxide.
Single-Replacement Reactions:
- When one element replaces another element in a compound, a single replacement reaction has taken place. - When this happens a new compound is formed and an element is released. - AY + B --> A+ BY
How do you balance combustion equations?
- balance C's and H's FIRST. - Save oxygen for last.
do these if u feel like it bc they're mixed single-replacement rxns: (or just say what kind of rxn they are) 1) Sn(s) + NaNO3(aq) --> 2) FeCl2(aq) + 2K(s) --> 3) Zn(s) + H2SO4(aq) --> 4) 2HCI (aq) + Ca(s) --> 5) Cl2(g) + NaI(aq) --> 6) PbF2(aq) + Br2(l) -->
. 1) NR (metal + compound) 2) 2KCl (aq) + Fe(s) (METALS + COMPOUND) 3) ZnSO4(aq) + H2(g) (metal + acid) 4) H2(g) + CaCl2(aq) (metal + acid) 5) NaCl(aq) + I2 (s) (nonmetal + compound) 6) NR (nonmetal + compound)
Predicting products: 1.) Na(s) + Cl2(g) → 2.) 2Al(s) + 3F2(g) →
. 1.) NaCl (s) 2.) 2AlF3 (s)
· In the example: 2K(s) + Cl2(g) → 2KCl(s) 1. Why is there a "2" after Cl in Cl2(g)?: 2. Why is there a "2" in front of K(s)?: 3. Why is the product KCl instead of KCl2?:
. 1.) diatomic 2.) bc it had to balance out the 2 cl by doubling KCl so the K has to be doubled as well 3.) Bc the charge of Cl is 1- and the charge of K is 1+
Predict: 2Li(s) + H2SO4(aq) --> Ca (s) + 2HNO3 (aq) -->
. H2 (g) + Li2SO4 (aq) Ca(NO3)2 (aq) + H2 (g)
How many types of DR rxns are there?
1 type
What are the 2 types of decomposition?
1) Metal carbonate breaks down into metal oxide plus carbon dioxide 2) A binary compound breaks down into the pure elements
Visual Cues of Chemical Reactions
1) release or absorption of heat/light 2) gas formation 3) formation of a precipitate (a solid that forms when you mix two liquids together) 4) color change (I think sometimes she said? Idk)
Balance this: ___Ba(NO3)2 (aq) + ___Na2CrO4 (aq) --> ___BaCrO4 (s)+ ___NaNO3 (aq)
1, 1, 1, 2
Balance this: ___Zn(s) + ____HCl (aq) --> ____H2 (g) + _____ZnCl2(aq)
1, 2, 1, 1
Balance this: ___CH4 (g) + ___O2 (g) --> ___CO2 (g) + ___H2O (g)
1, 2, 1, 2
What are the three types of Single-Replacement reactions?
1. Metal + compound yields a compound + metal. 2. Nonmetal + compound yields a compound + nonmetal 3. Metal + acid yields a compound + hydrogen
What are the 5 basic types of chemical reactions?
1. Synthesis or combination 2. Decomposition 3. Single Replacement (or single displacement) 4. Double Replacement (or double displacement) 5. Combustion
Write the Combustion of C10H20
1C10H20 + 15O2 → 10H2O + 10CO2
What is the 1 type of DR rxn?
2 compounds --> 2 compounds
Predict the Products of: 6K(s) + Al2O3(aq) --> & Ag(s) + CrCl3(aq) -->
2Al (s) + 3K2O (aq) & NO REACTION
Write this out and then balance it: Solid aluminum plus aqueous hydrochloric acid yields aqueous aluminum chloride and hydrogen gas.
2Al(s) + 6HCl (aq) --> 2AlCl3 (aq) + 3H2 (g)
Predict product of: Fe2O3(s) + 3H2O(l)→
2Fe(OH)3 (aq)
Chemical Equation Ex.
2H2(g) + O2 (g) --> 2H2O(l)
What are two examples of the first type of synthesis reaction?
2K(s) + Cl2(g) → 2KCl(s) 2S(s) + 3O2(g) → 2SO3(g)
Sodium hydroxide is heated releasing water and forming solid sodium oxide.
2NaOH (s) /\--> H2O(l) + Na2O (s)
Predict the products of: Rb2S(s)
2Rb(s) + S(s)
Iron rusts in oxygen to form the solid red iron(III) oxide.
4Fe (s) + 3O2 (l?) Fe2O2 (s)
Glucose (C6H12O6) and oxygen gas are the products of sunlight on carbon dioxide and water vapor in the air.
6CO2 + 6H2O (g) C6H12O6 (g?) + 6O2 (g)
Write out the predict product: Solid potassium is added to liquid nitrogen.
6K (s) + N2 (l) --> 2K3N (s)
What is a reactant?
A starting substance in a chemical reaction. It appears on the left of the arrow in a chemical equation.
What should you assume about transition metals?
Assume transitions metals have a 2+ charge in synthesis reactions unless told otherwise (and unless you can figure out the charge thru the equation)
What is a double replacement reaction?
C + C --> C + C (both switch) - The ions of two compounds exchange places in an aqueous solution to form two new compounds. - AX + BY → AY + BX Example: 2KI(aq) + Pb(NO3)2(aq) → PbI2(s) + 2KNO3(aq)
Write the Combustion of CH4
CH4 + O2 --> CO2 + H2O
Predict the products of: Na2CO3(s)
CO2 (g) + Na2O (s)
Predict the products of: ZnCO3(s)
CO2(g) + ZnO(s)
binary compound examples:
CaBr2, AgCl, Rb2S
Write out this reactant in word form: Cl2(g) + 2KBr(aq) ⇒ Br2(l) + 2KCl(aq)
Chlorine gas reacts with aqueous potassium bromide to form liquid bromine and potassium chloride dissolved in water (can also say TO YIELD instead of TO FORM) (can also say aqueous potassium chloride instead of potassium chloride dissolved in water)
examples of metal + acid --> compound + H2
Co(s)+ HCl(aq) --> CoCl2(aq) + H2(g)
1) When I reacted two compounds, I observed that the reaction turned blue from yellow, changed from a liquid to a solid, and the beaker got cold. Which observations are indications of a chemical change?
Color change, solid formation, and heat absorbed
What kind of a reaction is the following: CH4(g)+2O2(g) → CO2(g) + 2H2O(g)
Combustion
To make sure the ____________________ is obeyed, we must balance chemical equations!
Conservation of Mass law
What kind of a reaction is the following: PbO2(s) → Pb(s) + O2(g)
Decomposition
What kind of a reaction is the following: HCl(aq) + KOH(aq) → H2O(l) + KCl(aq)
Double-Replacement
Nonmetal + compound --> compound + nonmetal examples?
F2(g)+ KCl(aq) --> KF(aq) + Cl2(g) Br2(l)+ PbI2(aq) --> PbBr2(aq) + I2(s)
P4(s) + 6H2(g) ⇒ 4PH3(g)
Gaseous nitrogen trihydride and aqueous hydrochloric acid yields ammonium chloride dissolved in water.
4NH3(g) + 3F2(g) ⇒ 3NH4F(s) + NF3(g)
Gaseous nitrogen trihydride and fluorine gas yields solid ammonium fluoride and nitrogen trifluoride gas
Predict the Products: Br2(l) + NaI(aq) --> I2(g) + LiF(aq) -->
I2 (s) + NaBr (aq) NO REACTION
What is a chemical reaction?
It is a process in which one or more substances may be transformed into one or more new substances.
ex. of DR rxn
K2CrO4(aq) +Ba(NO3)2(aq) BaCrO4(s) +2KNO3(aq)
Aqueous potassium nitrate and solid carbon yields aqueous potassium carbonate and gaseous carbon monoxide and nitrogen gas.
KNO3 (aq) + C (s) K2CO3 (aq) + CO (g) + N2 (g)
Metal carbonate breaks down into metal oxide plus carbon dioxide example:
Metal carbonate (CO3)2- --> metal (a metal) oxide (O2-) + carbon dioxide (CO2) ex.) CaCO3(s) --> CaO(s) + CO2(g)
What is the form of the second type of synthesis reaction?
Metal oxide + water --> metal hydroxide (always aqueous?)
Nitrogen plus calcium
N2 (g) + 3Ca (s) --> Ca3N2 (s)
Solid nickel(II) carbonate is heated and its mass becomes less. Write a balanced chemical equation and explain this observation.
NiCO3 (s) /\--> CO2 (g) + NiO (s) Triangle thing on the arrow to indicate heating
(aq)
Reactant or product is dissolved in water (aqueous) (ex. NaCl(aq)) (solution) (dissolved in water)
What kind of a reaction is the following: Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq)
Single-Replacement
What kind of reaction is the following: Aluminum is added to zinc nitrate solution resulting in the formation of zinc metal and aluminum nitrate solution. (write own equation)
Single-Replacement
1) 2Al(s) + 3H2SO4(aq) ⇒ Al2(SO4)3(aq) + 3H2(g)
Solid aluminum reacts with aqueous sulfuric acid to form aqueous aluminum sulfate and hydrogen gas
What kind of a reaction is the following: 2Li(s) + F2(g) → 2LiF(s)
Synthesis
Physical Change
The particles in the substance are rearranged. They are the same substance, same chemical formula, just a different form.
arrow with the word "cat" on it
The rxn used a catalyst
⇌ is used for
Used for reversible rxns (we never used these)
+ sign symbol in chemical equation is used to
Used to separate reactants or products
Metal + acid --> compound + H2 explained:
When a metal reacts with acid (HCl, H2SO4, HClO3): - the metal will replace the hydrogen - & form an ionic compound plus hydrogen gas - Remember metals form positive cations, which will bond with negative anions (from the acid)
what is a metal oxide (asked this earlier too)
a chemical compound that contains a metal chemically combined with oxygen MgO, Na2O, Cr2O3
What is a metal oxide?
a chemical compound that contains a metal chemically combined with oxygen ex.) CaO, K2O, Ag2O
What is a binary compound?
a compound composed of two elements
What is a metal carbonate?
a metal with carbonate (CO3)2- ex.) Na2CO3, Fe2(CO3)3
There must be the same number of each type of _______ on the _______ side as on the _______ side of the arrow.
atom, product, reactant
Examples of Chemical Reactions
o Iron reacting with oxygen to form rust o Natural gas is burned to heat homes o Grape juice ferments in the production of wine
Is ripping paper a physical or chemical change?
physical
(s) or down arrow
solid
Chemical Equation
symbols and formulas, the identities and relative amounts of the reactants and products in a chemical reaction.
Chemical Change
the particles are broken apart and the atoms are rearranged into new particles forming a new substance.
what is a metal hydroxide?
metal + OH - Mg(OH)2, NaOH, Cr(OH)3
What can the 2 pure elements --> 1 compound be between?
metal + nonmetal (ionic) & nonmetal + nonmetal (covalent)
(g) or up arrow
gas
arrow pointing to right with triangle on top of it or the word "heat"
indicates heat is supplied to reaction
(l)
liquid state
Is burning paper a chemical or physical change?
chemical
In a chemical reaction, atoms are neither _______ nor __________.
created, destroyed
Activity Series of Halogens
· A nonmetal can also replace another nonmetal in a compound (type #2) - This replacement is usually limited to halogens. - The activity series of halogens decreases as you go down the group. (So you just have to look at group 17 from top to bottom) - Same rules for replacement apply as the metals. - Ex. Chlorine can replace bromine but not fluorine. Examples: - Chlorine will replace bromine from a compound (works bc chlorine is above bromine) -Cl2(g)+ 2NaBr(aq) 2NaCl(aq)+Br2(l) - Chlorine will not replace fluorine from a compound (chlorine is not above fluorine so no) - Cl2(g)+ CaF2(aq) --> no reaction - F > Cl > Br > I
Double-Replacement Rxn
· It's like... - Double date and you switch dates. - "Double flip-flop " ·- The cations and the anions switch dates. - AX + BY --> AY + BX
Decompositon
· One compound decomposes (splits-up) into two or more compounds and/or elements. · The exact opposite of synthesis reactions.
Diatomic Molecule
· a molecule composed of two of the same atom. · These molecules are found in nature as a diatomic molecule - very very rarely by themselves. · Remember the seven diatomic molecules: H2, N2, O2, F2, Cl2, Br2, I2