FINAL EXAM- Reactions and reaction types Flashcards Preview

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Flashcards in FINAL EXAM- Reactions and reaction types Deck (21)
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1
Q

Law of conservation of mass

A

atoms are neither created nor destroyed in a chemical change

2
Q

Composition

A

aka synthesis. Many reactants⇒one product. Opposite of decomposition

3
Q

types of composition

A
  • 2 types
  • Metals with Halogens- Ex. Na(s)+Cl2(g)⇒2NaCl(s)
  • With oxides (end in O)- Ex. CaO(s)+H2O(l)⇒Ca(OH)2(s)
4
Q

Decomposition

A

One reactant⇒many products

5
Q

Types of decomposition

A
  • 6 types
    a) Electrolysis
  • Use electricity to break the bond
  • Ex. H2O(l)⇒2H2(g)+O2(g)
    b) Binary Decompositon
  • Take elements in compound and break them apart
  • Ex. 2HgO(s)⇒2Hg(l)+O2(g)
    c) Metal Carbonate breaks to form metal oxide+carbondioxide
  • Ex. CaCO3(s)⇒(Δ above arrow) CaO(s)+CO2(g)
    d) Metal hydroxide to form metal + water
  • Ex. Ca(OH)2(s)⇒(Δ above arrow)CaO(s)=+H2O(l)
    e) Metal chlorate to form a metal chloride and oxygen
  • Ex. 2KClO3(s)⇒2KCl(s)+3O2(g)
    f) Tertiary acid to form an oxide and water
  • Ex. H2CO3⇒⇐CO2(g)+H2O(l)
  • ⇒⇐=could go both ways (not specific to this type of reaction, just in general)
6
Q

Single replacement

A

When there’s an element and a compound that form an element and a compound and the element replaces its like element in the compound, activity series permitted.

  • X+AB⇒AX+B
  • X+AB⇒XB+A
  • Both above are cation replacements
  • Y+AB⇒AY+B
  • Above is anion replacement
  • Cation replacement- metal replaces metal
  • Anion replacement- nonmetal replaces nonmetal
  • Use activity series of elements to determine if an element can replace or not
  • Ex. Li+NiO⇒Li2O+2Ni
  • Metals fight metals and nonmetals fight nonmetals
  • Metal and nonmetal always together
  • Whichever element is higher on the list wins the fight
  • Ex. BaS+Mg⇒NR (no reaction) because Ba is higher on the list so he wins the fight and gets to keep S
  • Ex. F2+NaBr⇒NaF+Br2 because F is higher on the list and wins the fight. F2 and Br2 because they are diatomic elements
7
Q

Double replacement

A
  • 2 compounds for both reactants and products, peaceful switch with no fight.
  • AB+XY⇒AY+XB
  • Positive/metal is always written first
  • Ex. 2NaCl(aq)+Pb(NO3)2(aq)⇒2NaNO3(aq)+PbCl2(s)
  • Compound for both reactants and products
8
Q

Neutralization

A

aka water forming.

  • Type of Double replacement
  • Acid+Base⇒Salt+water
  • HX+YOH⇒YX + HOH
  • Acids start with H (except water) and bases end in OH
  • In chemistry, salt is all ionic compounds except acids and base
  • Ex. HCl(aq)+KOH(aq)⇒KCl(aq)+HOH(l)
  • Ex. 2H(NO)3+Ca(OH)2(aq)⇒2HOH(l)+Ca(NO3)2(aq)
9
Q

Combustion

A
  • Complete Combustion
  • Hydrocarbon (H/C/O) + (excess) Oxygen ⇒(Δ above arrow) Carbon Dioxide+water
  • Ex. C2H5OH+O2⇒CO2+H2O
  • Incomplete combustion
  • Hydrocarbon+(limited)O2⇒CO+H2O (carbon monoxide) or C+H2O(carbon)
10
Q

Solubility rules

A

Chart that allows you to determine if a compound is soluble in water

11
Q

Products

A

A substance that forms in a chemical reaction

12
Q

Reactants

A

a substance or molecule that participates in a chemical reaction

13
Q

Coefficients

A

(big number in front of the substance symbol)= number of particles in the substance, used to balance.

14
Q

Endothermic reaction

A

Energy+reactants⇒products=endothermic

15
Q

Exothermic reaction

A

Reactants⇒Products+Energy=exothermic

16
Q

Symbols in reactions

A
  • Reactants yield sign ⇒ products
  • Plus sign separates reactants/products
  • S=Solid
  • L=Liquid
  • G=Glas
  • Aq=aqueous- dissolved in water- water doesn’t take place in the reaction
  • Coefficient- (big number in front of the substance symbol)= number of particles in the substance
  • Subscripts- used to write the formula corrects so that we have a net charge of zero
  • Catalyst- speeds up the reaction without changing its structure
  • up arrow indicates g, don’t need to put it in parenthesis
  • Sometimes down is used instead of (s) for a precipitate, don’t put in parenthesis
  • Δ=add heat for reaction to occur
17
Q

Know how to balance reactions from words and symbols

A
  • Coefficients are added in front of molecules, formula units, or atoms to balance the total number of each atoms in the equation.
  • Ex. 6Li+Sr3N2⇒2Li3N+3Sr
  • Ex. 2C8H18+25O2⇒16CO2+18H2O
  • Originally C8H18+25/2 O2⇒8CO2+9H2O
  • In this case, everything was doubled
  • When writing compound, make sure metal/+ goes first, then nonmetal/-
18
Q

Know how to determine reaction type

A
  • Many reactions ⇒one product= synthesis
  • One reactant⇒many products=Decomposition
  • Element+compound⇒ Element+compound=single replacement
  • 2 compounds for both reactants and products=double replacement
  • Acid+Base⇒Salt+water= water forming/neutralization
  • Hydrocarbon (H/C/O) + (excess) Oxygen ⇒(Δ above arrow) Carbon Dioxide+water= combustion
19
Q

Predict the products in a reaction

A
  • Determine reaction type from reactants
  • Follow pattern to determine products
  • Write formulas for products correctly (use subscripts)
  • Balance equation using coefficients
20
Q

Know how to indicate an exothermic or endothermic reaction in a balanced equation

A
  • Indicate an exothermic reaction by having energy as one of your products
  • Indicate an endothermic reaction by having energy as one of your reactants
21
Q

Determining phase of matter

A
  • All ionic compounds are solids at room temperate unless there’s water around and they are soluble
  • Ionic= cation (+) + Anion (-)
  • All metals besides mercury are solids at room temperature. Ex. Li(s)
  • Not all nonmetals are gases, just the ones on Mrs. Howards period table. Ex. O2(g)
  • Nobel gases are always gases. Ex. Ne(g)
  • Always check chart when possible to determine solubility