Question

QUESTION 1 According to the following thermochemical equation, what mass of HF (in g) must react in order to produce 345 kJ of energy? Assume excess SiO2. SiO2(s) + 4 HF(g) SiF4(g) + 2 H20) AH®rxn = -184 kJ 1079 150.9 173 g 37.59 QUESTION 2 The value of AH® for the reaction below is -1107 kJ: 2Ba (s) + O2(g) + 2Bao (s) How many kJ of heat are released when 5.75 g of Bao (s) is produced? 96.3 kJ 56.9 kJ 20.8 kJ OOOO 23.2 kJ

Answer 1

D SiOLS) +448fg) - Sifylg) + 2H2011) - Allrxu = -18465 18465 of energy need = unol if or 184 kJ of energy need=4x20 g HF 34565"» » » = 4x20 x 345 = 150 q HF) option (by 184

8) 384(+ 0, 0 -2ao (4) 2 mol Bao yield = energy or 2x153.33g BaO » - -110741 . energy 5.15g Bao yield=-1107 SAS 2x153:33 =-20.76kI or $20.8 kJ XM energy energy Option (c) correct.