MOLECULAR FORMULAS EXERCISE 1: MOLECULAR FORMULAS LEVEL 1 A H 2 O C 2 H 6 C C 2 H 6 O D CO 2 E F C 4 H 8 O CHN EXERCISE 2: MOLECULAR FORMULAS LEVEL 1 A HNO C 3 H 6 O C C 2 H 2 D C 6 H 5 NO E C 5 H 8 O 2 S 2 F C 8 H 14 N 4 O EXERCISE 3: MOLECULAR FORMULAS LEVEL 2 A Carbon: 1, hydrogen: 3, fluorine: 1 Carbon: 6, hydrogen: 12, oxygen: 6 C Nitrogen: 2, sulfur: 1, oxygen: 2 D Carbon: 4, hydrogen: 9, nitrogen: 1, oxygen: 2
EXERCISE 4: MOLECULAR FORMULAS LEVEL 3 A C 7 H 8 NSr C 10 H 6 N 2 OClF
WORD EQUATIONS EXERCISE 5: WORD EQUATIONS LEVEL 1 A C iodine + chlorine iodine trichloride hydrogen + oxygen water. sodium + chlorine sodium chloride. EXERCISE 6: WORD EQUATIONS LEVEL 2 A C methaan hydrogen + carbon hydrogen sulfide + oxygen water en sulfur dioxide zinc + oxygen zinc oxide EXERCISE 7: WORD EQUATIONS LEVEL 3 A C trinitrotoluene carbondioxide + water + nitrogen + carbon acetone + oxygen water + carbon dioxide iron + oxygen iron(ii)oxide
ALANCING REACTION EQUATIONS EXERCISE 8: MOLECULAR RATIO LEVEL 1 A 10 4 C 1000 D 500.000 EXERCISE 9: ALANCING EQUATIONS LEVEL 1 A 2 Ca + O 2 2 CaO 4 K + O 2 2 K 2 O C 4 Fe + 3 O 2 2 Fe 2 O 3 D 2 Pb + O 2 2 PbO EXERCISE 10: ALANCING EQUATIONS LEVEL 2 A H 2 + Cl 2 2 HCl 3 Mg + N 2 Mg 3 N 2 C N 2 + 3 H 2 2 NH 3 D 2 H 2 O 2 2 H 2 O + O 2 EXERCISE 11: ALANCING EQUATIONS LEVEL 2 A P 4 + 5 O 2 2 P 2 O 5 2 NaN 3 2 Na + 3 N 2 C CO + 2 H 2 CH 3 OH D 2 KClO 3 2 KCl + 3 O 2
EXERCISE 12: ALANCING EQUATIONS LEVEL 2 A C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O C 6 H 12 O 6 2 C 2 H 5 OH + 2 CO 2 C H 2 SO 4 + 2 Cu Cu 2 SO 4 + H 2 D Fe(OH) 3 + 3 Na 3 NaOH + Fe (should be in R.E. with groups) EXERCISE 13: ALANCING EQUATIONS LEVEL 2 A 4 NH 3 + 5 O 2 4 NO + 6 H 2 O SO 2 + 2 H 2 O + r 2 H 2 SO 4 + 2 Hr C 4 HCl + O 2 2 Cl 2 + 2 H 2 O D 2 H 2 SO 4 + 2 Fe Fe 2 (SO 4 ) 2 + 2 H 2 (should be in R.E. with groups) EXERCISE 14: ALANCING EQUATIONS LEVEL 3 A 2 Al + Fe 2 O 3 Al 2 O 3 + 2 Fe 4 FeS + 7 O 2 2 Fe 2 O 3 + 4 SO 2 C 2 Fe(OH) 3 + 3 H 2 6 H 2 O + 2 Fe EXERCISE 15: ALANCING EQUATIONS LEVEL 3 A PCl 5 + 4 H 2 O H 3 PO 4 + 5 HCl 2 As + 6 NaOH 2 Na 3 AsO 3 + 3 H 2 C Fe 2 O 3 + 3 CO 2 Fe + 3 CO 2
REACTION EQUATIONS WITH GROUPS EXERCISE 16: R.E. WITH GROUPS LEVEL 1 A 2 NaOH + K 2 S 2 KOH + Na 2 S CaCO 3 + 2 Cu Cu 2 CO 3 + Ca C AlPO 4 + 3 Cu Cu 3 PO 4 + Al EXERCISE 17: R.E. WITH GROUPS LEVEL 2 A 3 H 2 SO 4 + 2 Fe Fe 2 (SO 4 ) 3 + 3 H 2 3 KOH + H 3 PO 4 K 3 PO 4 + 3 H 2 O C Fe 2 (CO 3 ) 3 + 6 Na 3 Na 2 CO 3 + 2 Fe EXERCISE 18: R.E. WITH GROUPS LEVEL 3 A 3 CaCl 2 + 2 Na 3 PO 4 Ca 3 P 2 O 8 + 6 NaCl 2 Fe 2 (CO 3 ) 3 + Pb 3 (PO 4 ) 4 4 FePO 4 + 3 Pb(CO 3 ) 2 C 2 Fe(OH) 3 + 3 Cl 2 3 H 2 O 2 + 2 FeCl 3
COMUSTION REACTIONS EXERCISE 19: COMUSTION REACTIONS LEVEL 1 A CO 2 + SO 2 CO 2 + H 2 O C H 2 O + SO 2 D CO 2 + H 2 O + SO 2 EXERCISE 20: COMUSTION REACTIONS LEVEL 1 A CS 2 + 2 O 2 CO 2 + 2 SO 2 2 C 2 H 6 + 7 O 2 4 CO 2 + 6 H 2 O C C 4 H 10 O + 6 O 2 4 CO 2 + 5 H 2 O EXERCISE 21: COMUSTION REACTIONS LEVEL 2 A C 4 H 8 + 6 O 2 4 CO 2 + 4 H 2 O 2 H 2 S + 3 O 2 2 H 2 O + 2 SO 2 C 2 C 4 H 8 O + 11 O 2 8 CO 2 + 8 H 2 O EXERCISE 22: COMUSTION REACTIONS LEVEL 3 A 2 C 4 H 4 O + 9 O 2 8 CO 2 + 4 H 2 O 2 C 4 H 10 + 13 O 2 8 CO 2 + 10 H 2 O C 2 C 3 H 6 S + 11 O 2 6 CO 2 + 6 H 2 O + 2 SO 2
MAKING REACTION EQUATIONS EXERCISE 23: MAKING REACTION EQUATIONS LEVEL 1 A 2 NaCl 2 Na + Cl 2 CH 4 + 2 O 2 CO 2 + 2 H 2 O C C + O 2 CO 2 EXERCISE 24: MAKING REACTION EQUATIONS LEVEL 1 A I 2 + 3 Cl 2 2 ICl 3 2 C 2 H 6 + 7 O 2 4 CO 2 + 6 H 2 O C 2 H 2 + O 2 2 H 2 O EXERCISE 25: MAKING REACTION EQUATIONS LEVEL 2 A 4 H 2 + CO 2 2 H 2 O + CH 4 2 C 12 H 26 + 37 O 2 24 CO 2 + 26 H 2 O C S 8 + 8 O 2 8 SO 2 EXERCISE 26: MAKING REACTION EQUATIONS LEVEL 2 A 2 Al 2 O 3 4 Al + 3 O 2 2 C 8 H 18 + 25 O 2 16 CO 2 + 18 H 2 O C 2 C 2 H 6 S + 9 O 2 4 CO 2 + 6 H 2 O + 2 SO 2
EXERCISE 27: MAKING REACTION EQUATIONS LEVEL 2 A 2H 2 O + C 2 H 2 + CO 2 2 C 6 H 14 + 19 O 2 12 CO 2 + 14 H 2 O C CS 2 + 3 O 2 CO 2 + 2 SO 2 EXERCISE 28: MAKING REACTION EQUATIONS LEVEL 3 A 6 HNO 3 + 2 Fe 2 Fe(NO 3 ) 3 ) + 3 H 2 C 3 H 6 O + 4 O 2 3 CO 2 + 3 H 2 O C 2 C 2 H 6 S 2 O 2 + 9 O 2 4 CO 2 + 6 H 2 O + 4 SO 2 EXERCISE 29: MAKING REACTION EQUATIONS LEVEL 3 A 3 H 2 SO 4 + 2 Al Al 2 (SO 4 ) 3 + 3 H 2 C 2 H 5 OH + 3 O 2 2 CO 2 + 3 H 2 O C 2 C 3 H 8 SO + 11 O 2 6 CO 2 + 8 H 2 O + 2 SO 2
UNITS EXERCISE 30: UNITS LEVEL 1 A C D 3.0 g = 3000 kg 2.0 dm 3 = 2.0 L 5.4 kg = 5400 g 7.2 ml = 0.0072 L EXERCISE 31: UNITS LEVEL 2 A C 2.0 mg = 0.0000020 kg 2.0 cm 3 = 0.0020 L 8.2 kg = 8200 g D 9.1 ml = 0.0091 dm 3 EXERCISE 32: UNITS LEVEL 3 A 4.0 g/l = 4.0 kg/m 3 C 2.4 g/cm 3 = 2400 g/l 5.7 ton = 5700000 g D 6.2 ml = 0.0000062 m 3
LAVOISIER S LAW EXERCISE 33: LAVOISIER S LAW LEVEL 2 A The total mass of the starting substances is always equal to the total mass of the reaction products. Therefore, the answer is 72 grams. ecause atoms do not disappear (they rearrange to for new molecules) and because the number of atoms stays the same, their combined mass stays the same as well. EXERCISE 34: LAVOISIER S LAW LEVEL 3 16.0 + 128.0 = 144.0 grams.
MOLECULAR MASS EXERCISE 34: MOLECULAR MASS LEVEL 1 A 32.0 u C 160.0 u 256.8 u D 48.0 u EXERCISE 35: MOLECULAR MASS LEVEL 2 A 46.0 u C 46.0 u 102.0 u D 180.0 u EXERCISE 36: MOLECULAR MASS LEVEL 3 A 88.0 u C 85.0 u 60.1 u D 78.0 u
MASS RATIO EXERCISE 37: MASS RATIO LEVEL 1 A 30 : 60. This could be simplified to 1 : 2, but does not have to be done. 60 : 40. This could be simplified to 3 : 2, but does not have to be done. EXERCISE 38: MASS RATIO LEVEL 2 A 8.0 : 1.0 28.0 : 6.0 (of 14.0 : 3.0) EXERCISE 39: MASS RATIO LEVEL 3 A 32.0 : 22.0 (of 16.0 : 11.0) 8.0 : 22.0 (of 4.0 : 11.0)
CALCULATE MASS RATIO EXERCISE 40: CALCULATE MASS RATIO LEVEL 1 A 32.0 : 4.0 6.0 : 28.0 C 108.0 : 96.0 D 256.0 : 256.8 EXERCISE 41: CALCULATE MASS RATIO LEVEL 2 A 32.0 : 36.0 6.0 : 34.0. C 204.0 : 96.0 D 256.8 : 512.8 EXERCISE 42: CALCULATE MASS RATIO LEVEL 3 A 32.0 : 36.0 6.0 : 34.0. C 204.0 : 96.0 D 256.8 : 512.8
CALCULATIONS I EXERCISE 43: MASS CALCULATIONS LEVEL 1 (3.0/7.0)*4.0 = 1.7 g EXERCISE 44: MASS CALCULATIONS LEVEL 1 (1.5/23.0)*35.5 = 2.3 g EXERCISE 45: MASS CALCULATIONS LEVEL 2 Mass ratio iron : iron oxide = 55.8 : 7..8 (2.5/55.8)*71.8 = 3.2 g EXERCISE 46: MASS CALCULATIONS LEVEL 2 Mass ratio oxygen : copper(i)oxide = 16.0 : 143.0 (3.0/16.0)*143.0 = 26.8 g EXERCISE 47: DICHTHEID LEVEL 2 Mass ratio aluminium : aluminium oxide = 27.0 : 51.0 (7.0/27.0)*51.0 = 13.2 g EXERCISE 48: MASS CALCULATIONS LEVEL 3 Mass ratio calcium : calcium chloride : calcium = 111.0 : 40.0 (3.0/111.0)*40.0 = 1.1 g EXERCISE 49: MASS CALCULATIONS LEVEL 3 Mass ratio calcium : oxygen = 5.0 : 2.0 (5.0/5.0)*2.0 = 2.0 g
CALCULATIONS II EXERCISE 50: MASS CALCULATIONS LEVEL 1 Mass ratio H 2 : O 2 = 4.0 : 32.0 (4.0/4.0)*32.0 = 32.0 g EXERCISE 51: MASS CALCULATIONS LEVEL 1 Mass ratio H 2 : N 2 = 6.0 : 28.0 (5.0/6.0)*28.0 = 23.3 g EXERCISE 52: MASS CALCULATIONS LEVEL 2 Mass ratio O 2 : FeS = 224.0 : 287.2 (18.0/224.0)*287.2 = 23.1 g EXERCISE 53: MASS CALCULATIONS LEVEL 2 Mass ratio CaCl 2 : NaCl = 333.3 : 351.0 (22.0/333.3)*351.0 = 23.2 g EXERCISE 54: DICHTHEID LEVEL 2 30.0*1.98 = 59.4 g CO 2 Mass ratio CO 2 : C 6 H 12 O 6 = 264 : 180 (59.4/264)*180 = 40.5 g
EXERCISE 55: MASS CALCULATIONS LEVEL 3 Mass ratio Na 3 AsO 3 : NaOH = 383.3 : 240.0 (0.400/383.3)*240.0 = 0.25 g 2 As + 6 NaOH 2 Na 3 AsO 3 + 3 H 2 EXERCISE 56: MASS CALCULATIONS LEVEL 2 PCl 5 + 4 H 2 O H 3 PO 4 + 5 HCl Mass ratio HCl : PCl 5 = 36.5 : 208.5 (3.5/36.5)*208.5 = 20.0 g
SURPLUS EXERCISE 57: SURPLUS LEVEL 1 A Mass ratio SnO 2 : H 2 = 150.5 : 4.0 (25.0/150.5)*4 = 0.7 g Mass ratio H 2 : SnO 2 = 4.0 : 150.5 (3.0/4.0)*150.5 = 112.9 g C You can explain this in two ways: To allow all the SnO 2 to react (exercise A), 0.7 g H 2 is needed. However, there is 3.0 g H 2 so there is more H 2 than necessary. Therefore, H 2 is in excess. To allow all the H 2 to react (exercise ), 112.9 g SnO 2 is needed. However, there is 25.0 g SnO 2 so there is not enough SnO 2. So H 2 is in excess. The surplus of H 2 is 3.0 0.7 = 2.3 g EXERCISE 58: SURPLUS LEVEL 2 Mass ratio KOH : H 3 PO 4 = 168.3 : 251.4 (4.5/168.3)*251.4 = 6.7 g H 3 PO 4 There is more than 6.7 g H 3 PO 4 so H 3 PO 4 is in excess with 11.0 6.7 = 4.3 g
EXERCISE 59: SURPLUS LEVEL 3 A Mass ratio KNO 3 : H 2 CO 3 = 202.2 : 62.0 (12.0/202.2)*62.0 = 3.7 g There is more H 2 CO 3 than necessary, so H 2 CO 3 is in excess with 12.0 3.7 = 8.3 g. Use KNO 3 for further calculations since all of it (all 12.0 g) reacts. If you want to use H 2 CO 3, use 3.7 g (the maximum mass that can react) as mass of substance that reacts. Mass ratio KNO 3 : K 2 CO 3 = 202.2 : 138.2 (12.0/202.2)*138.2 = 8.2 g K 2 CO 3 Mass ratio KNO 3 : HNO 3 = 202.2 : 126.0 (12.0/202.2)*126.0 = 7.5 g HNO 3