Chapter 4 - Self Review

2.When the following reaction is balanced, what is the stoichiometric coefficient on sulfuric acidKOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET H2O K2SO4the balanced reaction is 2 KOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow.gif MERGEFORMATINET 2 H2O K2SO4. 3.Which ion is in Cr(ClO4)3the ions that make up Cr(ClO4)3 are Cr3 and ClO4. The subscripted 3 means that there are three of the perchlorate ions for each chromium (III) ion. 5.In the following reaction, if 4 moles of chromium(III) perchlorate react, how many moles of potassium carbonate are also used upCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3From the balanced equation the mole ratio is 2 Cr(ClO4)3 to 3 K2CO3, so 4 moles of Cr(ClO4)3 use 6 moles of K2CO3 6.In the following reaction, if 1 mole of both reactants is mixed, which is the limiting reactantCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3The stoichiometric coefficients in the balanced reaction show that 3 moles of potassium carbonate are needed for only 2 moles of chromium(III) perchlorate. Since we started with equal amounts of reactants, the potassium carbonate will be used up first. 7.What is an ion in NO2This is a molecular compound, not an ionic compound. Molecular compounds do not contain ions. 8.In the following reaction, if 10.0 g of K2CO3 completely reacted, how many grams of chromium(III) carbonate are madeCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)310.0 g K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/138.21 g) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol Cr2(CO3)3/3 mol K2CO3) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (224.02 g/1 mol) 5.40 g 9.In the following reaction, if 2 moles of chromium(III) perchlorate react completely, how many moles of chromium (III) carbonate are madeCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3The stoichiometric coefficients are also mole ratios. The balanced equation (question 21) shows that 2 moles of Cr(ClO4)3 make 1 mole of Cr2(CO3)3, 10.How many atoms of gold (Au) are in 1.12 mg of pure gold1.12 mg INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 g/1000 mg) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/196.97 g) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (6.022 x 1023 atom/1mol) 3.42 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1018 atoms 11.What is the percent composition of oxygen in Li2OPercent composition is g O/g Li2O INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 100 (16.00/29.88) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 100 53.6 12.When sulfur makes an ion, the formula and name will beSince sulfur is in group 6A, it needs to gain two electrons to have the electron configuration of a noble gas. Since it gains electrons, it has a negative charge. As a monoatomic anion, the suffix is changed to ide. 13.In the following reaction, if 1.0 mol KOH and 1.0 mol of H2SO4 are mixed, how many moles of reactant are left overKOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET H2O K2SO4mol KOH INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol H2SO4/2 mol KOH) 0.50 mol H2SO4 used. 1.0 mol 0.50 mol 0.50 mol. 14.Which of the following is a product of the combustion of a hydrocarbonA combustion reaction reacts the hydrocarbon (which contains hydrogen and carbon) with oxygen. The products of such are reaction are always carbon dioxide and water. 15.If a reaction has a 45 yield and a theoretical yield of 2.50 g, what is its actual yieldPercent yield actual/theory INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 100, so actual (theory/100) 45(2.5/100) 1.13 16.How many moles of nickel are in 1 mole of nickel(II) sulfateThe atom ratio in a compound is the same as the mole ratio. The formula is nickel(II) sulfate NiSO4, one nickel per formula unit. 17.How many moles of fluorine are in 9.2 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12_q.gif MERGEFORMATINET 1023 molecules of carbon tetrafluorideThere are 6.022 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1023 molecules in a mole. So 9.2 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1023 molec CF4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/6.022 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1023 molec) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (4 mol F/1 mol CF4) 6.1 mol. 18.In the following reaction, if 7.18 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12_q.gif MERGEFORMATINET 1010 molec of Cr(ClO4)3 react, how many molecules of KClO4 also reactCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3Stoichiometric coefficients represent molecule ratios as well as mole ratios, so7.18 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1010 molec Cr(ClO4)3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (3 molec KClO4/2 molec Cr(ClO4)3) 1.08 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1011 molec. 19.In the following reaction, if 1.0 mol of KOH is mixed with 1.0 mol H2SO4, what is the limiting reactantKOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET H2O K2SO4According to the balanced reaction, 1 mole of sulfuric acid requires 2 moles of potassium hydroxide, so KOH will run out first. 20.What is the stoichiometric coefficient on KClO4 in the following reactionCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3The balanced reaction is 2 Cr(ClO4)3 3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow.gif MERGEFORMATINET 6 KClO4 Cr2(CO3)3 22.In the following reaction, if 5.00 g of Cr(ClO4)3 are mixed with 7.00 g of K2CO3, how much reactant is left overCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3If Cr(ClO4)3 is the limiting reactant, then the amount of K2CO3 needed is5.00 g Cr(ClO4)3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/350.35 g) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (3 mol K2CO3/2 mol Cr(ClO4)3) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (138.21 g/1 mol) 2.95 g of K2CO3 used up. So 7.00 g to start 2.95 g used up 4.05 g left over. 23.An ic ending on the name of a transition metal means thatThe old system on naming depends on knowing what the common charges are for each element. The ic ending is for the higher charge ous is for the lower charge. Its complexity is the reason a new one is used. 24.What is the percent of oxygen in manganese(II) nitrateThe formula of manganese(II) nitrate is Mn(NO3)2. Therefore its molar mass is 178.94 g. The mass of oxygen in this compound is 6(16) 96 g. Percent oxygen 96/178.94 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 100 53.65 25.When Al3 combines with ClO4, the formula and name will beAs an ionic compound (metal/nonmetal), no prefixes are used. The cation is aluminum the anion is perchlorate. There must be three perchlorates to balance the 3 charge on the aluminum. 26.What is the formula of sodium carbonateSodium and carbon are a metal/nonmetal combination, thus an ionic compound. As an ion from group 1A, sodium ion is Na. Carbonate is the polyatomic ion CO32. For charges to cancel, there must be two sodiums to one carbonate. 27.How many moles are in 10.0 mL of Br2(l), which has a density of 3.12 g/mL10.0 mL INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (3.12 g/1 mL) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/159.8 g) 0.195 mol 28.Which of the following is an alkali metalAlkali metals are group 1A. Cs is the only choice in that column. 29.The limiting reactant isThe limiting reactant limits how much product you get because you run out of it first. 30.What is the name of ZnCl2It is an ionic compound therefore no prefixes are used. As a transition metal, normally there is a roman numeral. However, zinc is one of the exceptions. It does not use a roman numeral. 31.How many atoms are in 0.934 mol of copper0.934 mol INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (6.022 x 1023 atom/1 mol) 5.62 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 1023 atoms 32.Assuming an excess of KOH in the following reaction, how many moles of H2SO4 are needed to make 1.0 mol of waterKOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET H2O K2SO4mol water INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol H2SO4/2 mol water) 0.50 mol. 34.How many grams are in 2.13 mol of Pt2.13 mol INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (195.08 g/1 mol) 415 g 35.The name of HI isBinary acids of halogens are named as hydrohalogenic acid. 36.In the following reaction, if 7.00 g of K2CO3 completely reacts to make 3.00 g of Cr(CO3)3, what is the percent yield of the reactionCr(ClO4)3 K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET KClO4 Cr2(CO3)3Theoretical yield is determined from 7.00 g K2CO3 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/138.21 g) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol Cr(CO3)3/3 mol K2CO3) INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (224.02 g/1 mol) 3.78 g. Percent yield 3.00 g/3.78 g INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET 100 79.4 37.In the following reaction, if 1.0 mol KOH and 1.0 mole of H2SO4 are mixed, how many moles of water are madeKOH H2SO4 INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/equation_arrow_q.gif MERGEFORMATINET H2O K2SO4KOH is the limiting reactant, so1.0 mol KOH INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (2 mol water/1 mol KOH) 2.0 mol water 38.What is the empirical formula of a compound that is 43 carbon and 57 oxygenAssuming 100 g of compound, 43 g C and 57 g of O. Then 43g INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/12 g) 3.58 mol C and 57 g INCLUDEPICTURE http//www.wwnorton.com/chemistry/images/times_12.gif MERGEFORMATINET (1 mol/16 g) 3.56 mol of O, which give a 11 mole ratio. An empirical formula is the simplest ratio. 39.If the empirical formula of a compound is CH2O and its molecular weight is 180 g/mol, what is its molecular formulaThe empirical formula is the simplest ratio. The apparent molecular weight of CH2O is about 30 g/mol. The actual molecular weight is180. This is six times the apparent weight, so the formula must be six times the empirical formula. 40.Which of the following is not part of Daltons atomic theoryDaltons theory was developed before the discovery of protons.