Chemical reactions Flashcards
What is a combustion reaction?
A combustion reaction is a reaction that produces CO2 and H2O that looks like this:
CxHy + O2 = CO2 + H2O
or this:
CxHyOz + O2 = CO2 + H2O
or this:
CxHy(OH)z + O2 = CO2 + H2O
What is a synthesis/combination reaction?
In a synthesis/combination reaction, you’re usually taking smaller things and making it into something larger. Almost all two element reactions and synthesis reaction. (A+B –> AB)
Example: Mg + O2 –> MgO
What is a decomposition reaction?
In a decomposition reaction, you’re usually breaking down something into smaller things. (AB –> A + B)
Example: MgO3 + Heat –> MgO + CO2
What is a single replacement reaction/single displacement reaction?
In a single replacement/single displacement reaction, you’re switching things around (A + BC = AC + B)
Example: Zn + CuCl2 –> ZnCl2 + Cu
What is a double replacement/double displacement reaction?
In a double replacement/double displacement reaction, you’re switching things around (AB + CD = AD + BC)
Example: HCl + NaOH -> NaCl + H2O
What is a precipitation reaction?
A precipitation reaction is a type of double replacement/double displacement reaction where you’re mixing two aqueous phases and get a solid product.
Example: AgNO3 (aq) + NaCl (aq) –> AgCl (s) + NaNO3 (aq)
What is a neutralization reaction?
A neutralization reaction is a type of double replacement/double displacement reaction where you mix a strong acid (aq) with a strong base (aq) and get water and salt
Example: HCl (acid) + NaOH (base) –> NaCl (salt) + H2O (water)
What is a gas evolution reaction?
A gas evolution reaction is a type of double replacement/double displacement reaction where you mix two aqueous phases and get a gas.
Example: Na2S (aq) + HCl (aq) –> NaCl (aq) + H2S (g)
What time is a double replacement/double displacement reaction NOT considered a reaction?
When you mix aqueous reactants and get only aqueous products.
What is a redox reaction?
A redox reaction is a reaction that involves the transfer of electrons.
What is the reactivity series of metals?
The reactivity series determines how reactive a metal is. It is used to determine whether or not a single replacement/single displacement reaction will take place.
Name the reactivity series from least to most reactive.
Highly Unreactive:
Pt, Au, Ag, Hg, Cu, Bi, Sb
Comparison:
Hydrogen
Reacts with acids:
Pb, Sn, Ni, Co, Cd, Fe, Cr, Zn, Mn, Al, Mg
Reacts with water:
Ca, Sr, Ba, Li, Na, K
How can we use the reactivity series of metals to determine if a single replacement/single displacement reaction will occur?
In A + BC –> AC + B
If A is higher than B on the reactivity series (that is, more reactive), then the single replacement reaction will most likely occur.
Example: Fe + 2HCl –> FeCl2 + H2 will occur because Fe is higher than H on the reactivity series.
What is the difference between oxidation and reduction?
Oxidation is a loss of electrons. Reduction is a gain of electrons.
How do you write the total ionic equation?
First, take everything in their aqueous phase and separate it into their respective elements (Egs,: 2HCl –> 2H^+ + 2Cl^-)
Note: Subscripts are converted to coefficients (Al2 –> 2Al)
Note: Certain substances may be in their aqueous phase, but they may not ionize completely so you shouldn’t separate them (weak acids, weak bases)
