CALCULATING REACTING QUANTITIES

Transcription

1 MODULE 2 14 WORKSHEET WORKSHEET For multiple-hoie questions 1 5 irle the letter orresponding to the most orret nswer. 1 The lned eqution for the urning of utnol (C 4 H 9 OH) is given elow: C 4 H 9 OH(l) 6O 2 (g) 4CO 2 (g) 5H 2 The mount of oxygen needed to urn 2 mole of utnol is: d 2 moles 4 moles 6 moles 12 moles 2 For the following retion: Whih of the following is NOT true? d PSO 4 (s) H P 2 HSO 4 One mole of led sulfte produes one mole of led ions. The retion tkes ple in wter. Both produts preipitte out of solution. The eqution is lned. 3 A student hs two identil flsks. One flsk is filled with 1 mole of ron dioxide (CO 2 ) t temperture of 25ºC nd the other flsk is filled with 2 moles of hydrogen (H 2 ) t temperture of 0ºC. The rtio of numer of moleules of CO 2 to the numer of moleules of H 2 is: 4:1 2:1 1:1 d 1:2 4 The lw of omining volumes ws proposed y: d Dlton Gy-Luss Avogrdo Newton CALCULATING REACTING QUANTITIES Syllus referene Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14

2 5 A ompound of mss 2.41 g is otined when 1.77 g olt is reted ompletely with oxygen. The empiril formul of the ompound is: CoO Co 2 O 3 Co 3 O 2 d Co 3 O 4 6 Lrge rystls of white nhydrous opper(ii) nitrte re heted strongly nd prtiulr type of retion ours. The eqution for the retion is: 2Cu(NO 3 (s) 2CuO(s) 4NO 2 (g) O 2 (g) 5.0 moles of opper(ii) nitrte re pled in ruile nd heted. The hnge in the mount of sustne remining s it is heted over period of time is shown elow How would the mss of opper(ii) oxide t the end of the retion ompre with the mss of opper(ii) nitrte t the eginning of the retion? Mss of opper(ii) oxide will e less thn the mss of opper(ii) nitrte. How mny moles of opper(ii) nitrte hve deomposed fter six minutes? Approximtely 4 moles. Clulte the totl numer of moles of oxygen gs formed y the time the retion is ompleted. From the lned eqution, 2 moles Cu(NO 3 produe 1 mole O 2, so 5 moles Cu(NO 3 will produe 2.5 moles O 2. Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14

3 7 The eqution for the omustion of utne is: 2C 4 (g) 13O 2 (g) 8CO 2 (g) 10H 2 Clulte the numer of moles of: CO 2 produed in the omustion of 1 mole of C 4 4 mol H 2 O produed in the omustion of 3 moles of C 4 15 mol O 2 onsumed in the omustion of 0.6 moles of C 4 8 How mny moles of oxygen gs would e otined if: 3.9 mol 0.80 moles of potssium hlorte (KClO 3 ) is deomposed y heting into potssium hloride nd oxygen? 2KClO 3 2KCl 3O mol 0.24 moles of merury(ii) oxide is deomposed y heting into merury nd oxygen gs? 2HgO 2Hg O mol moles of mgnesium oxide is ompletely dissolved in nitri id (HNO 3 ) to form solution of mgnesium nitrte. Clulte the numer of moles nd msses of: nitri id required mgnesium nitrte formed MgO 2HNO 3 Mg(NO 3 H 2 n(hno 3 ) 0.60 mol m (HNO 3 ) 0.60 ( ) 38 g n(mg(no 3 ) 0.30 mol m (Mg(NO 3 ) 0.30 ( ( )) 44 g Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14

4 10 Exess dilute sulfuri id ws dded to 3.00 g of lium ronte (CCO 3 ) to form lium sulfte, ron dioxide nd wter. Clulte the msses of: sulfuri id onsumed 2.94 g ron dioxide produed 1.32 g lium sulfte formed 4.08 g 11 Dilute hydrohlori id ws dded to zin until no further retion ourred. Write lned eqution for the retion. Zn(s) 2HCl(q) ZnCl 2 (q) H 2 (g) If mole of zin hloride ws formed wht mss of zin reted? n(zncl 2 ) mol n(zn) mol m(zn) g Wht mss of zin hloride would e produed if mole of hydrohlori id reted with exess zin? n(hcl) mol n(zncl 2 ) mol m(zncl 2 ) ( ) 2.7 g 12 Wht volume of oxygen is required for the omplete omustion of 125 ml of utene gs (C 4 H 8 ) nd wht volume of ron dioxide is formed? (All volumes re mesured t the sme temperture nd pressure.) C 4 H 8 (g) 6O 2 (g) 4CO 2 (g) 4H 2 V(O 2 ) ml V(CO 2 ) ml Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14

5 13 Nikel rets with ron monoxide to form gseous nikel ronyl. When exess nikel ws reted with 500 ml CO, 125 ml nikel ronyl ws formed t the sme temperture nd pressure. Assuming ll the CO reted, wht is the formul of nikel ronyl? Explin how you dedued this. Ni(CO) ml CO produed 125 ml nikel ronyl; this mens tht 4 mol CO produed 1 mol nikel ronyl so 1 mol nikel ronyl must ontin 4 mol CO hene Ni(CO) Propne is used s fuel in mping stoves. The eqution for the omplete omustion of propne is: C 3 H 8 (g) 50 2 (g) 3CO 2 (g) 4H ml of propne is urnt in n exess of oxygen. Clulte: the volume of oxygen onsumed V(O 2 ) ml the volume of ron dioxide produed V(CO 2 ) ml (All volumes mesured t the sme temperture nd pressure.) 15 A silver oin ws nlysed nd found to ontin only silver nd opper g of this oin ws dissolved in onentrted nitri id nd the resultnt solution diluted. Retion of the solution with exess hydrohlori id yielded g of silver hloride. Clulte the perentge of silver in the smple. m(agcl) g n(agcl) / ( ) mol n(ag) mol m(ag) g %Ag 0.79 / % Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14

6 16 A smple of iron wire rets with oxygen to form iron(iii) oxide. If 3.58 g of the wire yields 5.00 g of the iron(iii) oxide, lulte the perentge purity of the iron. 97.7% 17 The smelting proess of hlopyrite, CuFeS 2, is represented y the following eqution: 2CuFeS 2 (s) 5O 2 (g) 2Cu(s) 2FeO(s) 4SO 2 (g) If 22.0 kg of the hlopyrite rets nd the perentge yield for this proess is 95%, lulte the mss of opper formed. m(cufes 2 ) 22 kg g n(cufes 2 ) / ( ) mol n(cu) (95% yield) mol m(cu) g 7.2 kg Copyright 2008 MGrw-Hill Austrli CONQUERINGCHEMISTRY PRELIM MODULE 2 WS 14