CHEM CH.#3 – Flashcards
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atomic element
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exist in nature as single atoms
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molecular element
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exist in nature as molecules composed of two or more atoms of that element
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ionic compound
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usually composed of a metal cation and nonmetal anion; polyatomic ions also exist
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molecular compound
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usually composed of two or more covalently bonded nonmetal atoms
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Explain how to name binary ionic compounds. How do you name an ionic compound if it contains a polyatomic ion?
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[name of cation (metal) + base name of anion (nonmetal)+ide] Polyatomic ions: same except uses name of the polyatomic ion instead of anion+ide
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Explain how to name binary & oxyacids
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binary acids: formed from a hydrogen & a nonmetal [hydro + base name of nonmetal + ic acid]
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What kinds of conversion factors are inherent in chemical formulas? Give example
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mass of compound--->moles of compound--->moles of element--->mass of element
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How can a molecular formula be obtained from an empirical formula? What additional info is required?
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-step 1: determine molecular mass in grams -step 2: divide molecular mass of compound (mu) by molecular mass (g) of empirical formula -step 3: round quotient to nearest integer -step 4: multiply rounded # by all subscripts, using product as new subscripts ??????????
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What are functionalized hydrocarbons? Give example
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an organic compound that contains only carbon & hydrogen ???????????
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Classify each element as atomic or molecular: a) neon b) flourine c) potassium d) nitrogen
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???????????
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Classify each compound as ionic or molecular: a) CO2 b) NiCl2 c) NaI d) PCl3
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a) molecular b) ionic c) ionic d) molecular ?????
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Write a formula for the compound that forms between calcium & each polyatomic ion: a) hydroxide b) chromate c) phosphate d) cyanide
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????????????/
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Name each ionic compound: a) Mg3N2 b) KF c) Na2O d) Li2S e) CsF f) KI g) SrCl2 h) BaCl2
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a) magnesium nitride b) potassium flouride c) sodium oxide d) lithium sulfide e) caesium flouride f) potassium iodide g) strontium chloride h) barium chloride
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Give the name from the formula or the formula from the name for each hydrated ionic compound: a) CoSO4 * 7H2O b) iridium(III) bromide tetrahydrate c) Mg(BrO3)2 * 6H2O d) potassium carbonate dihydrate
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??????????
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Name each molecular compound: a) CO b) NI3 c) SiCl4 d) N4Se4 e) I2O5
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a) carbon monoxide b) nitrogen triiodide c) silicone tetrachloride d) tetranitrogen tetraselenide e) diiodine pentaoxide
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How many moles in 25.5 g NO2?
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-obj:find moles of molecule from grams of molecule -STEP#1: find molar mass of molecule: NO2 has 1 atom of N & 2 atoms of O 1 atom of N has molar mass of 14.01g/mol 1 atom of O has molar mass of 16.00g/mol therefore, molar mass will be found by: 14.01g/mol of N + 16.00g/mol of O + 16.00g/mol of O =46.02g/mol of NO2 -STEP#2: multiply amount of CO2 given by the molar mass of NO2: (25.5 g NO2)*(1/46.02 mol/g NO2) = .554 mols of NO2
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How many moles in 38.2 g KNO3?
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1 atom of K has molar mass of 39.10g/mol 1 atom of N has molar mass of 14.01g/mol 1 atom of O has molar mass of 16.00g/mol 39.10+14.01+16.00+16.00+16.00= 101.11g/mol KNO3 (38.2 g KNO3)*(1/101.11 mol/g KNO3) = .378 mols of KNO3
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How many moles in 1.25 kg CO2?
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n=m/mm m=1.25(1000)= 1250 C: 12.011(1)=12.011 O: 16(2)=32 mm=12.011+32= 44.011 n=1250/44.011 =28.4 mol
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How many moles in 155.2 kg Na2SO4?
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n=m/mm m=155.2(1000)= 155200 Na: 22.99(2)=45.98 S: 32.065(1)=32.065 O: 16(4)=64 mm=45.98+32.065+64= 142.045 n=155200/142.045 =1093 mol
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Calculate the mass percent composition of carbon in CH4
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-step#1: find atomic mass of each element in the molecule: atomic mass of C: 12.01g/mol atomic mass of H: 1.01g/mol -step#2: find mass combination of each element: mass contribution of C= 1 X 12.01g/mol mass contribution of H:= 4 X 1.01g/mol -step#3: find the total molecular mass of the molecule: molecular mass of CH4= 12.01g/mol + 1.01g/mol + 1.01g/mol + 1.01g/mol + 1.01g/mol= 16.05g/mol -step#4: find the mass percent composition of each element: mass percent composition of C= mass contribution of C/molecular mass of CH4 X 100% =(12.01g/mol) / (16.05g/mol) X 100% = 74.83%
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Calculate the mass percent composition of carbon in C2H6
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C: 12.011(2)=24.022 H: 1.0079(6)=6.0474 24.022+6.0474=30.0694 =(24.022/30.0694) (100%) =79.89%
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Calculate the mass percent composition of carbon in C2H5Cl
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C: 12.011(2)=24.022 H: 1.0079(5)=5.0395 Cl: 35.453(1)=35.453 24.022+5.0395+35.453= 64.5145 =(24.022/64.5145) (100%) =37.24%
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Determine the number of moles of hydrogen atoms in each sample: a) 0.0885 mol C4H10 b) 1.3 mol CH4 c) 2.4 mol C6H12 d) 1.87 mol C8H18
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How many molecules are in each sample? a) 6.5 g H2O b) 389 g CBr4 c) 22.1 g O2 d) 19.3 g C8H10
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a) (6.5)*(6.02 X 10^23) / molar mass(18) = 2.2 X 10^23 molecules b) (389)*(6.02 X 10^23) / [12.01+(79.9*4)]=331.611= 7.06 X 10^23 c) (22.1)*(6.02 X 10^23) / [16*2]=32 = 4.16 X 10^23 d) (19.3)*(6.02 X 10^23) / [(12.01*8)+(1.01*10)]=106.18 =1.09 X 10^23
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Calculate the empirical formula for the stimulant based on its elemental mass percent composition: caffeine: C 49.48%, H 5.19%, N 28.85%, O 16.48%
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carbon: (49.48gC)*(1mol/12.01gC)= 4.1199 hydrogen: (5.19gH)*(1mol/1.01gC)= 5.1386 nitrogen: (28.85gN)*(1mol/14.01gC)= 2.0592 oxygen: (16.48gO)*(1mol/16.00gC)= 1.0306 divide them all by lowest number (in this case oxygen) =C4H5N2O
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Calculate the empirical formula for the stimulant based on its elemental mass percent composition: nicotine: C 74.03%, H 5.19%, N 17.27%
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carbon: (74.03gC)*(1mol/12.01gC)= 6.164 hydrogen: (5.19gH)*(1mol/1.01gC)= 5.1386 nitrogen: (17.27gN)*(1mol/14.01gC)= 1.2327 =C5H4N
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hemi
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1/2
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tetra
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4
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hepta
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7
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nona
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9
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molecular formula
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notation indicating the number of atoms of each element present in a compound
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empirical formula
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notation indicating the ratios of the various elements present in a compound, without regard to the actual numbers
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percent by mass
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the fraction, by weight, of one component of a compound
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calculating mass percent composition of a molecule
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step#1: find atomic mass of each element in the molecule step#2: find mass combination of each element step#3: find the total molecular mass of the molecule step#4: find the mass percent composition of each element
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formula unit
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smallest collection of ions that is electrically neutral
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naming ionic compounds
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[name of cation] + [base name of anion+-ide]
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naming ionic compounds with a metal cation of a variable charge
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[name of cation] + [(charge of cation in Roman numerals in parentheses)] + [base name of anion+-ide]
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naming hydrated ionic compounds
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when water molecules are part of the compound, the # of water molecules must be included in the name.
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naming molecular compounds
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steawp + [name of first element] + steawp + [base name of second element+-ide]
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formula mass
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=(# of atoms of first element in chem formula X atomic mass of first element) + (# of atoms of second element in chem formula X atomic mass of second element) +.....
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mass percent
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=(mass of element/mass of compound) X (100%)
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Balance the equation: P4(s) + Cl2(g) ==> PCl3(s)
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P4 + 6Cl2 ==> 4PCl3
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Balance the equation: SO3(g) ==> SO2(g) + O2(g)
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2SO3 ==> 2SO2 + O2
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Balance the equation: H3PO4(aq) + CaO(s) ==> Ca3(PO4)2(aq) + H2O(I)
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2H3PO4 + 3CaO ==> Ca3(PO4)2 + 3H2O
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How many grams Cr are contained in 43.7 g chromium (III) sulfate?
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What is the mass of oxygen, in grams, present in 28.9 g chromium (III) sulfate?
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What is the mass % of iron in iron (III) oxide?
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Fe2O3 Fe: 55.845(2)= 111.69 O: 16(3)= 48 111.69+48=159.69 (111.69/159.69)(100%)= 69.9%
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Name each compound: a) KOH b) lead (II) sulfate c) lead (IV) sulfate d) SnBr2 e) iron (III) nitrate f) P4O10 g) cobalt (II) chloride hexahydrate h) S2Cl2
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a) potassium hydroxide b) Pb2SO4 c) Pb(SO4)2 ???? d) tin (II) bromide ???? e)
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Name each ionic compound: a) MgF2 b) Al2S3 c) ZnO d) potassium chloride e) calcium nitride f) lithium bromide
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polyatomic ion
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-group of atoms that are covalently bonded together w/ an overall charge not equal to 0 -names ending w/ -ite or -ate = polyatomic (w/oxygen) (exceptions: hydroxide, cyanide, ammonium, peroxide)
