Question
Given the reactions 1 and 2 below 1. H2(g) + I2(s) -- 2HI(g) 2. 2H2 + O2(g) --2H2O(g) 3. 4HI(g) + O2(g) -- 2I2(s) +2H2O(g) A. determine Hr and Ur I have the solution to this problem and it states reaction3=(-2) x reaction1 + reaction2 andng= -1 My question is where does the (-2) come from and isng = -1 because in reaction3: 4moles of product -5 moles of reactant= -1. Thank you for your time. Given the reactions 1 and 2 below 1. H2(g) + I2(s) -- 2HI(g) 2. 2H2 + O2(g) --2H2O(g) 3. 4HI(g) + O2(g) -- 2I2(s) +2H2O(g) A. determine Hr and Ur I have the solution to this problem and it states reaction3=(-2) x reaction1 + reaction2 andng= -1 My question is where does the (-2) come from and isng = -1 because in reaction3: 4moles of product -5 moles of reactant= -1. Thank you for your time. I have the solution to this problem and it states reaction3=(-2) x reaction1 + reaction2 andng= -1 My question is where does the (-2) come from and isng = -1 because in reaction3: 4moles of product -5 moles of reactant= -1. Thank you for your time.
Explanation / Answer
1. H2(g) + I2(s) .............>2HI(g) 2. 2H2 + O2(g) ...........>2H2O(g) 3. 4HI(g) + O2(g) ...........> 2I2(s)+ 2H2O(g) Now, multifly equation 1 by 2 and then substractfrom equation 2 , you get eqaution 3 2H2(g) + O2(g) + 4HI(g) ...........> 2H2O(g) + 2H2(g) +2I2(s) or O2(g) + 4HI(g) ...........>2H2O(g) + 2I2(s) ................................................. n g = number of moles of gaseousproducts - number of moles of gaseous reactants 1. H2(g) + I2(s) .............>2HI(g) 2. 2H2 + O2(g) ...........>2H2O(g) 3. 4HI(g) + O2(g) ...........> 2I2(s)+ 2H2O(g) Now, multifly equation 1 by 2 and then substractfrom equation 2 , you get eqaution 3 2H2(g) + O2(g) + 4HI(g) ...........> 2H2O(g) + 2H2(g) +2I2(s) or O2(g) + 4HI(g) ...........>2H2O(g) + 2I2(s) ................................................. n g = number of moles of gaseousproducts - number of moles of gaseous reactants In reaction 3 , number of moles ofgaseous products = 2 mol number of moles of gaseous reactants = 4+1 = 5mol n g = 5 -2 = 3