Chemistry 112 Final – Flashcards
Unlock all answers in this set
Unlock answers| An orbital has positive and negative amplitudes because electrons are waves |
| True |
| A central atom that has 2 single bonds and one double bond will have a tetrahedral electron pair geometry |
| False- Trigonal planar |
| A molecule that has trigonal bipyramidal geometry has 6 electron pairs on the central atom |
| False- only has 5 electron pairs |
| A central atom that has sp2 hybridization will have a bond angle approximately of 109.5 degrees |
| False---- 120 degrees because it is a trigonal planar |
| A pi bond experiences free rotation around the bond |
| False- only sigma bonds do |
| A double bond has one pi bond and one sigma bond |
| True |
| Bonds result from the constructive interference of overlapping orbitals according to |
| Valence bond theory |
| The geometry around a central atom is due to the repulsion of electron pairs according to |
| VSEPR |
| Bonds are formed by sharing or transferring electrons in order to become like a noble gas according to |
| The octet rule |
| Electrons degenerate orbitals singly before pairing up according to |
| Hund's Rule |
| What changes when an orbital hybridizes |
| the shape, direction, and energy |
| If an atom has sp hybridization how many pi and sigma bonds can it form |
| two pi bonds and two sigma bonds |
| What happens when sodium chloride is dissolved in water? |
| the sodium are surrounded by the oxygen and the chlorine is surrounded by the hydrogen |
| Is Cu3(PO4)2 soluble and why? |
| No because of the phosphate |
| is Cr(NO3)2 soluble and why? |
| Yes because of the nitrate |
| Is Mg(CH3COO)2 soluble and why |
| yes because of the acetate |
| is calcium sulfate soluble and why |
| no because of the calcium ion |
| Is CCl4 soluble and why |
| no becuase no rules apply |
| What happens if a solution become over saturated? |
| Some solute should precipitate |
| If a solution is above its solubility amount it is considered |
| supersaturated |
| If a two things are miscible and homogeneous they have |
| similar properties like polarization, bonding, solubility and weight |
| When an element becomes an cation, what happens and where from |
| it loses electrons from the (s) shell first |
| What constitutes an exception in electron configuration |
| if the outermost shell can be half full or completely full |
| What is the difference between electron configuration and orbital diagrams |
| electron configuration is simply numbers and letters and orbital diagrams dipict each electron in its shell or subshell |
| A central atom that has trigonal planar geoumetry will experience what hybridization |
| sp2 |
| A central atom that has two single bonds and three lone pairs of electrons on it.; The central atom will hybridize to what? |
| sp3d |
| The hybridization of C in CH4 is |
| sp3 |
| A central atom that has 2 single bonds and one double bond has a trigonal planar electron pair geometry |
| True |
| An electron configuration can use the symbol of an alkali metal to represent core electrons |
| False- it uses Noble gases not alkali metals |
| A molecule with; tetrahedral geometry has a bond angle of 109.5 |
| True |
| Is KCN soluble and why |
| yes because it has potassium |
| Is Fe2O3 soluble and why |
| No because it has O with a -2 charge |
| is CH3Cl soluble in water? |
| Yes because it is polar |
| is barium phosphate soluble and why |
| no because it has phosphate |
| Is Al2(SO4)3 soluble and why |
| yes because it has sulfate |
| Is CO2 soluble and why |
| no because it has london dispersal forces instead of hydrogen bonding |
| What makes substances soluble in other substances |
| like dissolves like, similar weight, bonding, and polarity |
| If a solution is below its solubility can it dissolve more solute? |
| Yes |
| Are CS2 and C6H6 miscible? |
| Yes because they both have LDF forces |
| Are H2O and C6H12 miscible |
| No because water has hydrogen bonding and the other has LDF |
Describe what the equation of each of the following look like Strong electrolyte: Weak electrolyte: Non electrolyte: |
:single arrow, ions :double arrows, ion :single arrow, no ions |
| A solutions concentration given in molarity is temperature independent |
| False, molarity is temperature dependent |
| Molality compares the amount of solute present to the mass of the solution |
| False, it compares it to the mass of the solvent not solution |
| Ppb and ppm are often used with very dilute solutions |
| True |
| What is the equation for weight percent? |
wt%= mass solute mass solution |
Which characterizes each of the following Strong electrolyte: Weak electrolyte: non electrolyte: |
:soluble ionic compound or strong acid : insoluble ionic compound :No ions |
| Can you use hybridized orbitals in a pi bond |
| No |
| Steps on how to find mass of solute from grams solute and molality of the solution |
1. rearrange molality equation 2. convert grams to kilograms 3. Change mols to grams |
| Steps to find final concentration when given initial concentration, initial volume, and final volume |
1. write out the equation M1V1=M2V2 2. Solve for x |
| Steps to find molarity and molality of a solution from % by mass and density |
1. Assume 100g solution 2. subtract g solute from g solution to get g solvent 3. converty solvent into kilograms 4. Divide total g of solution by density to get volume 5. convert to L 6. determine moles of solute 7. divide by volume of solution to get Molarity 8. divide moles solute by mass of solvent to get molality |
| According to Arrhenius, a base is defined as being something that----- when added to water |
| produces OH- |
| The number of solute particles (i) a molecule has is dependent on what |
| The number of ions it breaks up into |
| If two solutions have the same number of particles they will also have the same |
| vapor pressure |
| The fewer solute particles there are, the lower the------ will be |
| osmotic pressure and boiling point |
Identify the following Tb: R: Pa: n: m: |
:solution boing point :ideal gas constant : vapor pressure :moles :molality |
| Which of the following will have the lowest boiling point |
| pure water |
Explain what each of the following means Small K value: Large K value: |
: reactant is favored : product is favored |
| At equillibrium the rate of dissociation is equal to the rate of formation |
| True |
| The concentration of the product divided by the concentration of the reactant is equal to the same constant alway |
| no they could have a different ratio |
What happens is each instance Q>K: Q<K: |
The reverse reaction occurs
The forward reaction occurs |
| What is Kc |
Equillibrium constant It is the products over the reactants Solids are not included |
| When is an ice table required |
| When the initial values of the substance are given and if it is a weak acid or base |
What will the following do Increasing pressure: Adding a product: cooling the reaction: Remove a solid: Remove a reactant:
|
:move to less gas : move in the reverse : move in the foward :no effect :move in the reverse |
| List the strong acids |
| HCl, HBr, HI, HClO4, HNO3, H2SO4 |
| How to find vapor pressure above a solutin when given mass of solute and solvent and pure vapor pressure of the solvent is given. |
1. write equation vp=XaPa^0 2. write equation for Xa+ nsolv/nsolv+nsoln 3. determine moles from grams 4. plug into first equation |
| Finding the boiling point of an aqueous solution when given the grams solute and solvent and boiling point of solvent |
1. determine number of solute particles 2. figure out molality by getting moles and mass of solute and solvent 3. find delta by multiplying bp water by solute particles by molality 4. add boiling point of pure water to tempt derived
|
| Steps on fining equilibrium constant when given values at equlibrium and volume of the solution |
1. divide both mole values by the volume 2. plug into expression |
How to find number of moles of each is present at equillibrium when given the equilibrium constant and intial value of one and volume of solution
|
1. make ice table 2. set up equillibrium expression 3. substitute from ice and set equal to value given 4. solve for x 5. Plug x back into values from ice table |
| give two examples of pH neutral anions |
| Cl-, Br-, I-, NO3- or ClO4 |
| The conjugate acid has------- hydrogens than the conjugate base |
| 1 more hydrogen |
How to find the pH, the pOH and the H conentration when given the OH concentration
|
1. to get pOH take the negative log of the OH 2. to get the pH substract the pOH from 14 3. To find the H raise 10 to the negative pH |
| How to get the pKa from the Ka |
| take the negative log of Ka |
| What does lowest percentage ionization entail |
| weakest acid and smallest Ka |
| The stronger a weak acid is, the stronger a base its conjugate base is |
| false |
| The solution with the largest Ka |
| is the strongest acid |
| How do you make a buffer |
| a weak acid and conjugate base |
| How do you determine the pH from the Ka |
| the pKa+ the log of b/a is the pH |
| The equivilance point of an acid/ base titration |
| needs to be near the pKa of the indicator |
| What do common ions do |
| decrease the solubility |
| doing work and gaining heat |
| w- and q+ |
| What gives off heat |
| changing from a gas to a liquid |
| endothermic is-------- while exothermic is ------ |
| positive and negative |
| If a system has a driving force propelling it in the forward direction is it spontaneous? |
| yes |
