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)
How do you write net ionic equation?
The net ionic equation is the total ionic equation but the respective ions (that is, ions that are the same on both sides of the equation) are removed. If possible, simplify the coefficients afterwards.
Note: The same elements, even with the same coefficients, if they don’t have the same charge, they are not respective ions.
What is the reactivity series of halogens?
The reactivity series of halogens is the order of how reactive each halogen is.
Name the reactivity series of halogens (most to least)
Fl2, Cl2, Br2, I2, At, Ts
How can we use the reactivity series of halogens to determine if a single displacement reaction will occur?
A + BC = AB + C
If A is more reactive then C, the reaction will occur.
Example: Cl2 + 2NaBr –> Br2 + 2NaCl
What is a salt in chemistry?
Something that comes from an acid-base reaction.
H + OH always equals:
H2O (Water)
Write the chemical equation and net ionic equation for Na2CO3 + HCl
Na2CO3 + HCl –> 2NaCl + H2CO3 –> NaCl + H2O + CO2
Chemical Equation: Na2CO3 (aq) + 2HCl (aq) –> 2NaCl (aq) + H2O (l) + CO2 (g)
Total Ionic Equation:
2Na^+ + CO3^2- + 2H^+ + 2Cl^- –> 2Na^+ + 2Cl^- + H2O + CO2
Net Ionic Equation:
CO3 + 2H –> H2O + CO2
