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Mass percent composition
Random Mix
Chemical Equations
Solubility & Precipitation
Acid/Base, Gas, Redox
100
What is the relationship between an empirical formula and a molecular formula?
What is "an empirical formula gives the smallest whole-number ratio of each type of atom; the molecular formula is the ACTUAL number of atoms of each type of element in a compound; the molecular formula is a whole number ratio of the empirical formula"
100
What is the empirical formula molar mass?
What is "the sum of the molar masses of all the atoms in the empirical formula; molar mass is the mass of 1 mole of that substance"
100
When you are balancing a chemical equation, change only the ________, never the _________ [both must be correct for points].
What is "coefficients, subscripts"
100
A ______ ion is one that you do not include when writing out a net ionic equation.
What is "spectator ion"
100
True or False (explain your answer): reduction is when there is a gain of electrons.
What is "True: remember OIL RIG - oxidation is loss, reduction is gain"
200
A 2.45g sample of strontium completely reacts with oxygen to form 2.89g of strontium oxide. Calculate the mass percent composition of strontium in strontium oxide.
What is "2.45/2.89 x 100 = 84.8%"
200
Is the following a redox reaction? How can you tell? 4K(s) + O2(g) --> 2K2O(s)
What is "all combustion reactions are redox"
200
What is the term for when a substance is dissolved in water?
What is "aqueous, (aq)"
200
Is the following compound soluble? PbCO3
What is "no, see solubility table for carbonate - lead is not an exception"
200
When an acid and a base react together, what do they produce?
What is "water and salt"
300
Copper (II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine in grams contained in 28.5g of copper(II) fluoride.
What is "28.5g CuFl2 x (37.42g F/100g CuFl2) = 10.7g F)
300
Calculate the mass percent composition of O in calcium nitrate.
What is: "chemical formula: Ca(NO3)2; overall molar mass = 164.09g; molar mass of O in the compound = 6 x 16.00g = 96g; mass % composition of O = 96g/164.09g = 58.5%"
300
Name 4 things to look for when assessing whether a chemical reaction has taken place.
What is "color change, emission of light, emission or absorption of heat, formation of a solid, formation of a gas"
300
Complete and balance the following equation: NaC2H3O2(aq) + Pb(NO3)2(aq) -->
What is "no reaction; the potential products - PbC2H3O2 and NaNO3 are both soluble"
300
A beaker of nitric acid is neutralized with calcium hydroxide. Write a balanced molecular equation for this reaction.
What is "2HNO3(aq) + Ca(OH)2(aq) --> Ca(NO3)2(aq) + 2H2O(l)"
400
A compound containing carbon and chlorine has a molar mass of 284.77g/mol and an empirical formula of CCl. What is its molecular formula?
What is "molar mass/empirical mass = multiplier, n; 284.77/47.46 = 6 --> 6 x CCl = C6Cl6"
400
What is the mass of 6.022 x 10^23 atoms of aluminium?
What is "26.98g"
400
Write a balanced chemical equation for the following: solid lithium oxide reacts with liquid water to form aqueous lithium hydroxide.
What is Li2O(s) + H2O(l) --> 2 LiOH(aq)
400
Is the following equation correct? If not, correct the mistake: Cu(NO3)2(aq) + (NH4)2S(aq) --> CuS(s) + 2NH4NO3(aq) [you may use the book to look at necessary tables]
What is "correct!"
400
Name 3 common gases that we could see in a gas evolution reaction.
What is "Dihydrogen sulfide (H2S), Carbon dioxide (CO2) Sulfur dioxide (SO2), Ammonia (NH3)"
500
The rotten smell of a decaying animal carcass is partially due to a nitrogen-containing compound call putrescine. Elemental analysis of putrescine indicates that it consists of 54.50% C, 13.73%H, and 31.77%N. Calculate the empirical formula of putrescine.
What is "to solve this problem, you need to understand that 54.50% C also means that in a 100g sample of this compound, you'll have 54.50g of C - this will be your conversion factor. From there, you convert to moles of C using the molar mass (1 mol C / 12.01g C). Then you write your pseudoformula, and multiply it out to get the empirical (to the blackboard!); correct empirical formula = C2H6N
500
What kind of ions to Zinc and Silver form? [no book use allowed!]
What is: "Zn2+, Ag+"
500
Balance the equation on the slide...
What is (see answer on slide)
500
Write a complete ionic and net ionic equation to show the reaction of aqueous lead(II) nitrate with aqueous potassium sulfate.
What is "see slide"
500
Complete and balance the following equation: HC2H3O2 (aq) + LiHSO3 (aq) -->
What is "see slide"