Unit 4: atomic structure Flashcards
What’s a synthesis?
A + B –> AB
What’s a decomposition?
AB –> A + B
What’s a single replacement?
AB + C –> A + CB
What’s a double replacement?
AB + CD –> AD + BC
What’s a precipitation?
AB(aq) + CD(aq) –> AD(s) + CB(aq)
- Soluble reactants produce in an insoluble solid (precipitate)
What’s a combustion?
CnHn(aq) + H2(g) –> CO2(g) + H2O(g)
What’s oxidation-reduction reaction?
One or more electrons are transferred between reactants.
- Something solid at first with no charges transforms in an ionic molecule
What’s a neutralization reaction?
Acid and base react and form water and salt (ionic compound). The other product is water!
*Acid starts with H
*Base finishes with OH
Solute, solvent, solution?
- Solute is the powder that is dissolved
- Solvent is the dissolving medium. WATER IS THE UNIVERSAL SOLVENT.
- Aqueous solution is produced (aq).
Why is water the universal solvent?
- Polar covalent molecule
- Water can dissolve polar and ionic solutes!
- Some parts of the water are positive and other are negative.
What are more electronegative, metals or non-metals?
Non-metals, because they want to get electrons to have their shell full!
On the other hand, metals DON’T want the electron, they want to give it!
Ionic solutes?
- Solute ionic compounds are packed closely together, because of strong ionic forces and form structures called crystal lattices.
- Polar water molecules interact with the positive and negative ions of salt.
Polar covalent solutes?
- Polar covalent substances can also dissolve in water!
3 different types of equations?
1- Molecular equation: complete, balanced, neutral formulas of all species.
2- Ionic equation: ionic species are shown as ions.
3- Net ionic equation: equation without spectator ions that appear on both sides of the equation.
How to know the states in precipitation reactions?
- First balance equation and than write the products while looking at the positive and negative charges.
- Look at the solubility guidelines for ionic compounds in water in order to now if state stays aqueous or becomes solid.
What is M?
M = Molarity, which is the number of moles of solute per volume of solution in liters.
M - moles of solute/liters of solution
Concentration of ions?
- Ionic coumpouds separate into component ions when they dissolve in water!
- To find de concentration, you multiply the coefficient of the ion times the initial concentration
The 2 reactions occuring during a redox reaction?
- Oxidation: loss of one or more electrons
- Reduction: gain of one of more electrons
Acronyms to retain redox?
- LEO (Lose electron = oxidized)
- GER (gain electron = reduced)
Hal-cell reaction?
- It’s either an oxidation, or reduction, component of a redox reaction.
- Reduction half-cell reaction = gain
- Oxidation half-celle reaction = lost
Ionic vs covalent substances?
- Ionic: electrons are transferred and ions are formed
- Covalent: electrons are transferred, but ions are not formed
The 6 rules to assigning oxidation numbers?
1) ELEMENTS: oxidation number is always 0 for atoms in elemental state. (ex: K(s) = 0)
2) MONATOMIC ION: oxidation number = it’s charge. (ex: Fe2+ = +2)
*Halogens are usually -1, but if with oxygen, the oxidation number has to be calculated.
3) OXYGEN: Has oxidation number of -2, except peroxides that are -1.
4) NEUTRAL MOLECULE: Sum of the oxidation numbers equals 0 (it’s neutral)
5) POLYATOMIC IONS: Sum of xidation numbers equals charge of ions. (ex: NH4+ = +1)
6) HYDROGEN: oxidation number is +1 or -1
The oxidizing agent?
- It’s the substance that has been reduced that causes the oxidation of the other substance.
The reducing agent?
- It’s the substance that is oxidized that causes the reduction of the other substance.
