Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
AP Unit Exam
Bonding, IMF, VSEPR, Organic Chem, Solutions, Gases
| Question | Answer |
|---|---|
| What does a "polar molecule" mean? | A polar molecule is a molecule which has two opposite sides that are non symmetrical. One pole is like the "bully", it exerts a more attractive force to the other's electrons, like in water. |
| How can a molecule have no dipole moment | A molecule will have no dipole moment if it's geometry is completely symmetrical, like in linear, tetrahedral, octahedral or t-shapes. |
| What are resonance structures? | Different, but valid, Lewis Dot Structures that obey the octet for the same molecule. |
| Why are resonance structures needed? | Electrons are in constant motion, they are never localized, so more than one Lewis Dot diagram is possible. |
| What is the rule for the formal charge? | (Valence e- of the atom) - (valence e- assigned to the atom in the structure) |
| How do you determine which resonance structure is the best? | The formal charges should be as close to zero as possible. |
| What does VSEPR mean (what does it imply about electron placement)? | Non bonded pairs should be as far apart as possible, and each pair should be removed or added as opposites. |
| What does degenerate mean? | It means that [they] are equal. |
| What is hybridization? | When electrons from different orbitals hybridize to form a conjoined orbital, like "s" and "p" combine as "sp" when bonding. |
| Can atoms like O,C,N, or F ever have a dsp3 hybridization? | No, because they do not have a "d" block to which the electrons can move to. The non-metallic elements in period 3, however, do have an empty "d" block, so they can have a dsp3 hybridization. |
| What are sigma bonds? | Single bonds between electrons |
| What are pi bonds? | When double or triple bonds exist, a pi bond is created because the bonds don't actually touch each other. Rather, they are parallel. |
| How many sigma and pi bonds are in a single bond? How many sigma and pi bonds are in a double bond? How many sigma and pi bonds are in a triple bond? | a) 1 sigma bond and 0 pi bonds b) 1 sigma bond and 1 pi bond c) 1 sigma bond and 2 pi bonds |
| What are metalloids? | Metalloids are elements which have properties of both metals and non metals, they are: shiny, poor conductivity, malleability |
| How do you know if an element is a metalloid by looking at the Periodic Table? | One side of the element will be touching the staircase. |
| What is the octet rule? | Electrons will lose or gain (cation or anion) electrons to form a stable noble gas with 8 electrons in the valence shell. |
| Describe ionic bonds | -The transfer of electrons -Metals and nonmetals -High melting point and boiling point -Conduct as liquid, mostly solid -Soluble |
| Describe metallic bonds | -Sea of electrons -Metals only -High melting point and boiling point -Insoluble -Always conduct, and have other metallic properties |
| Describe covalent bonds | -Share electrons -Non metals only -Low melting point and boiling point -Insoluble unless polar -Never conduct -Create molecules |
| If the lattice energy is not enough, can a compound be made? | No, reactions must be exothermic! |
| Which compounds have more lattice energy? | Compounds in which the elements have higher chargers and the distance between atoms are much smaller. |
| What is sublimation? | When a metal goes from the solid phase to the gaseous phase. |
| Are bonds stronger or intermolecular forces? | Bonds are stronger! |
| What do intermolecular forces do? | They hold a substance together, it's the attraction between molecules. |
| Sbstances with strong IMF have (a) melting points, (b) boiling points and are most likely to be (c) at room temperature. | (a) high (b) high (c) solids |
| What is London Dispersion? | It is the weakest attraction between covalent (mostly non polar) molecules. The electrons of one atom attract the nucleus of another. This causes a temporary shift of electrons making one side of the molecule positive and the other negative. |
| What makes the London Dispersion force stronger? | If there are more electrons, the force will be stronger. |
| What is a dipole-dipole attraction? | They occur between polar molecules, and are stronger than LDF. The more polar a molecule is, the greater the force of attraction. |
| London Dispersion and Dipole-Dipole can also be called: | Van der Waals forces! |
| What is a hydrogen bond? | A very strong IMF that exists between hydrogen, fluorine, oxygen and nitrogen because the latter three have high electronegativities and make very polar substances. They have high melting and boiling points. |
| In C and SiO2, what happens with the IMF? | Network solids are formed, although they are covalently bonded. The VDW forces are much stronger than normal. |
| What are Ion-Dipole Attractions? | The strongest attraction exists between ionic compounds and polar compounds. Polar substances can ionize ionic substances due to strong attractions. |
| When should you use the Combined Gas Law? | When you are given two different conditions and asked to find a new volume/pressure/temperature. |
| What type of gases travel faster? Which are slower? | Lighter gases are faster. Heavier gases are slower. |
| When should PV=nRT be used? | When you are given information to find only one of the variables. No new and previous conditions. |
| Is PV=nRT reliable although it applies to ideal gases? | Yes, because the values are extremely close! |
| When temperature increases.... | volume increases |
| What are the three characteristics of an ideal gas? | 1. Do not attract or repel. 2. Have negligible volumes 3. Molecules are in constant, rapid, random and straight-line motion |
| When temperature increases.... | pressure increases |
| When pressure increases.... | volume decreases |
| What does Avogadro say about equal volumes of gases at the same temperature and pressure? | They have the same number of molecules |
| What is surface tension? | An elastic force on the liquid surface. The stronger the IMFs, the higher the forces and surface tensions. |
| What is viscosity? | Viscosity is a measure of a liquid's resistance to flow. The greater the IMF, the greater the viscosity and the slower it will flow. If you increase the temperature, viscosity decreases. |
| Define exothermic | When heat is given off (radiated) during a reaction |
| Define endothermic | When no heat is radiated, but a lot was absorbed for the reaction |
| On a phase change diagram, what do straight lines represent? | A phase change |
| How does the cooling curve differ from a heat diagram | They are opposites |
| In a triple point diagram, the triple point is when | a substance can exist as all three states simultaneously |
| In a triple point diagram, the critical point is when | the substance is entirely in the gaseous phase |
| Why is the slope on water's triple point diagram negative? | The liquid phase is denser than the solid phase |
| What are supersaturated solutions? | When more solute can be dissolved in a solvent than is normal at that temperature. They are heated, and then rapidly cooled, and a slight disturbance can cause the solute to come out. |
| What is the difference between Molality and Molarity? | Molality is mol of solute per kg of solvent, so it is not dependent on temperature unlike molarity. |
| What are colligative properties? | They depend on the number of solute particles, not on the type of solute. |
| Explain vapor pressure lowering | When you add a solute to a solvent, the vapor pressure of the solution is lower than that of the pure solvent |
| Explain boiling point elevation | When you add a solute to a solvent, the boiling point is higher than that of the bp of the pure solvent |
| Explain freezing point depression | When you add a solute to a solvent, the freezing point is lower than that of the fp of the pure solvent |
| What is osmosis? | Osmosis the process by which water will diffuse out of a semipermeable membrane to achieve equilibrium. |
| What is osmotic pressure? | The pressure needed to stop osmosis |
| In the formula for calculating osmotic pressure, what does pi stand for? | Nothing, it's just a variable. |
| Why do unsaturated hydrocarbons undergo addition? | They are unsaturated, so a double or triple bond can break up to include other elements. |
| What do saturated hydrocarbons undergo? | Addition |
| Saponification is | when a base is added to a fat to make soap |
| Polymerization is | the linking of a hydrocarbon to form long chains of plastics |
| Esterification is | when an alcohol and carboxylic combine to form a great smelling ester |
| Fermentation produces | ethanol and carbon dioxide from sugar |
| Combustion involves | hydrocarbons reacting with oxygen to produce CO2 and H20 |
| Cracking is | when large hydrocarbons are broken to form smaller ones |
| Memorize suffixes and functional groups | |
| What are isomers? | Isomers have the same formula, but they have different structures with different properties |
| What is the explicit formula for alkanes? | CxH2x+2 |
| What is the explicit formula for alkenes? | CxH2x |
| What is the explicit formula for alkynes? | CxH2x |
| Organic chemistry is the study of | carbon and hydrogen containing compounds |
| What is the difference between cis and trans isomers? | On a cis isomer, the hydrogens are all on one side, and in a trans isomer, they are on opposite sides. |
| Alcohols with more than one hydroxide group are known as | dihydroxy alcohols or trihydroxy alcohols |
| In a series, what is the prefix to name the first of the series? The second of the series? | "Form" and "Ace" respectively |
| Amines have or don't have oxygen? | Amines don't have oxygen |
| Do amides have oxygen? | Yes, they do. |
| How do you know if an alcohol is primary, secondary, or tertiary? | Find the carbon to which the functional group is linked to. If the carbon is touching one other carbon, then it is a primary alcohol, if it is touching two others, it is a secondary alcohol, and three others would be a tertiary. |
Created by:
Rehnuma32219
Popular Chemistry sets