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
Chemistry Final S2
| Question | Answer |
|---|---|
| What is the number of atoms in a mole of any pure substance called? | Avogadro's number; 6.02x10^23 |
| Consider 1 mol of Zn and 1 mol of Al: are they equal in mass? | No |
| Consider 1 mol of Zn and 1 mol of Al: are they equal in molar mass? | No |
| Consider 1 mol of Zn and 1 mol of Al: do they have the same number of atoms? | Yes |
| Consider 1 mol of Zn and 1 mol of Al: do they have the same atomic mass? | No |
| why is the atomic mass of an element not a whole number? | weighted average of all isotopes |
| what do the subscripts indicate in a formula? | how many atoms of each element |
| how many atoms of chlorine are in a molecule of carbon tetrachloride? | 4 |
| what happens when you change the subscript in a correctly written formula? | you change the compound |
| the molar mass of an element is the mass of one ______. | mass |
| True or False: To determine the molar mass of an element, one must know the element's atomic number. | False |
| what is the molar mass of calcium? | 40.08g |
| what is the empirical formula for a compound that is 31.9% potassium, 28.9 chlorine, and 39.2% oxygen? | KClO3 |
| What is the empirical formula for a compound that has the molecular formula C10H8O2? | (divide by 2); C5H4O |
| What is the percent composition of MgI2? | Mg= 8.74% I= 91.26% |
| Knowledge about what products are produced in a chemical reaction is obtained by which of the following: writing a word equation, inspecting the chemical equation, balancing the chemical equation, or laboratory analysis? | Laboratory analysis |
| if a chemical reaction has occurred, can the products have the same chemical properties as the reactants? | no |
| how do you know if a chemical reaction has taken place? | new products; a color chance, temperature change, or a state change |
| how do you indicate the state of matter for a reactant or a product in a chemical equation? | liquid, gas, or solid ; (l), (g), (s) |
| what is a precipitate? | insoluble solid that forms 2 liquids reacting |
| how is oxygen written in a chemical equation? | O2 |
| In a chemical reaction, the products always have: the same molecules, subscripts, atoms or coefficients as the reactants. pick one. | atoms |
| once you write the correct formula for a reactant in an equation, can you change the subscripts? Will you have the same formula in the products? | no; no |
| balancing equations means possibly adjusting the __________. | coefficients |
| write the formula for copper II sulfate. then react it with aluminum and predict the products. Now balance it. | 3CuSO4(aq)+ 2 AL(s) ---> Al(SO4)3 (aq)+ 3Cu(s) |
| what is a synthesis reaction? give an example. | A+B ---> AB; 2H2 + 02 ---> 2H20 |
| be able to tell the difference between a decomposition reaction and a single replacement reaction. | decomposition: AB ---> A+B single replacement: AB+ C ---> AC+B |
| what is the activity series and how does it work? | list of metals from metals activity. if a metal is above another on the list, it can replace any below it |
| when positive and negative ions combine during a double-displacement reaction, a ______ can form. | precipitate |
| what can you determine from a balanced equation (as far as the coefficient goes)? | mole to mole ratio |
| what is the mole ration of oxygen to hydrogen in the equation for the formation of water? | 1:2 ; 2H2+O2 ---> 2H2O |
| in the reaction of nitrogen gas with hydrogen gas producing ammonia gas), to calculate the mass of ammonia gas produced from 3.5L of nitrogen gas in excess hydrogen gas you would need to know ____ molar mass(es), ___ density(ies), ____ mole ratio(s). | balanced equation: N2+ 3H2 ---> 2NH3 2;1;1 |
| how do you know which is limiting and which is excess? | limiting: 3/2 moles O2 needed excess: ? mol 2H2O |
| what is the formula for percent yield? | A/T x 100 |
| the measured amount of product obtained in a chemical reaction is called the ____ yield | actual |
| how is the actual yield obtained? | through lab experiment |
| which is always less, theoretical yield or actual yield? | actual yield |
| for the reaction SO3+ H2O ---> H2SO4, calculate the percentage yield if 500g of sulfur trioxide react with excess water to produce 575g of sulfuric acid. | 500gSO3 x 1 mol SO3/80.1gSO3 x 1 mol H2SO4 x 98.1gH2SO4/ 1 molH2SO4 =612gH2SO4(t) %= 575G/612 x 100 = 93.95% |
| if you compare moles in a chemical reaction, you are looking at the mole ______. | ratio |
| show the factor label set-up for the calculation of moles of methane consumed in the reaction of methane (CH4) undergoing combustion if you produce 25g of carbon dioxide | (? mol) CH4+ 2O2 ---> CO2+2H2O 25gCO2 x 1mol/44.01gCO2 x 1 molCH4/1molCO2= 0.568molCH4 |
| how do you know if you have a limiting reactant problem? | you have to give amounts for reactants |
| what happens to a gas if the particles move farther apart? | the gas increases volume and expands |
| which phase of water would have the lowest density? | gases, vapor |
| do gases have a definite volume that does not vary from container to container? | no |
| what is the SI unite of pressure? | pascal; kPa |
| what is the standard temperature and pressure for a gas? | kelvin: 273K pressure: 1 atm st: 0 degrees |
| convert 0.64 atm to kPa. | 0.64 atm x 101.3kPa/ 1 atm= 64.8kPa |
| gas particles are in constant motion according to the _____________- ___________ theory | kinetic - molecular |
| what is the volume of a gas at a pressure of 0.855 atm, if the pressure was 0.77 atm and 160mL and the temperature remains constant. | (0.855 atm) V1= (.77atm)(160mL) ---> 144.1mL |
| if the pressure remains constant and a gas occupies a volume of 652mL at 25 degrees C, what volume will the gas occupy if the temperature increases at 60 degrees C. | 652mL/298K= x/333K x= 729mL |
| a sample of a gas has a pressure of 4 atm at 26 degrees C. what would the gas pressure be at 55 degrees C, if the volume remains constant? | 4atm/ 299K= P2/ 328K P2= 4.39atm |
| the particles exert attractive forces on each other in a _____ gas. | real |
| a _____ gas does not obey all the assumptions of the kinetic-molecular theory. | real |
| what can be calculated using the ideal gas law if the pressure, volume, and temperature are known? | PV= nRT 0.0821 atm x L/ R x mol |
| calculate the approximate volume of 0.8 mol sample of gas at 25 degrees C and a pressure 1.45atm. | (1.45atm)(V)= (.8mol)(0.0821)(298K) V= 13.5L |
| what is diffusion? | spreads from high concentration to low concentration |
| the molar mass of a gas can be calculated if one knows the _____ and volume of the gas at STP. | mass |
| circle all the following that are homogeneous : tap water, whole wheat bread, granite, an oil-water micture | tap water |
| carbon dioxide in water: which is the solute and which is the solvent? is carbon dioxide a solid, liquid, or gas. | Solute: Carbon dioxide (CO2) Solvent: water (H2O) gas |
| name 3 ways to express concentration | molarity, molality, ppt |
| what is the molarity of a solution that contains 0.303 mol KCl in 8.97L of solution? | 0.338 |
| an NaOH solution contains 2.80 mol of NaOH, and its concentration is 0.94M. What is its volume? | 2.8/ 0.94= 2.98L |
| the solubility of a substance at a given temperature can be expressed as amount of _____________ per amount of ___________. | solute; solvent |
| circle those that are soluble in water: potassium nitrate, silver, benzene, carbon tetrachloride | potassium nitrate |
| a compound that has effective poles in different (will)/(will not) most likely dissolve in water. | will |
| the formation of solid-liquid solution can either absorb or release __________. | heat |
| what is an electrolyte and give an example. is sugar an electrolyte? | a substance that conducts energy; salt water No, sugar isn't an electrolyte. |
| which if a molecular substance whose water solution conducts electricity: sugar, iron, liquid hydrogen or hydrogen chloride? | hydrogen chloride |
| molecules whose water solutions conduct current _________ in water. | ionize |
| nonelectrolytes do or do not form ions in solution. pick one. | do not |
| HCl is a molecular compound that _______ in water. | ionizes |
| electrolytes produce more moles of solute particles per mole of solute, which effects their ____________ properties differently. | colligative |
| bases taste | bitter |
| acids taste | sour |
| name the strong bases that are made with group 1 metals. | LiOH, NaOH, KOH, RbOH, CsOH |
| strong bases and acids are ________ electrolytes. | strong |
| Bronsted-Lowry definition of acids and bases emphasizes the role of _______. | protons |
| What is the neutralization reaction? | when an acid and a base react to form salt and water acid + base |
| What is amphoteric? | being able to act as an acid or a base |
| Kw is known as the ____________ and has a value of ____________. | self ionization constant ; 1x10^-14 |
| what is in pure water? | water molecules. CH-, H3O+ |
| what is the concentration of hydroxide ions in pure water? | 1.0 x 10^-7 |
| neutral solutions have a pH of ____, and acids are ______ than this. | 7; lower |
| what is the hydronium concentration of a solution with a pH of 8.7 | 2 x 10 ^-9 |
| What is the pH of 2 x 10 ^-6 M KOH solution? | 8.3 |
| define the equivalency point. | when equivalent quantities of H+ and OH- are present. |
| unknown concentration can be calculated after performing a ______ (not "experiment!) | titration |
Created by:
Elisabetmiguel
Popular Chemistry sets