CH 2200 Lecture Notes - Lecture 40: Touch 'N Go

Formation Reactions v2 Part A The standard heat of formation, Δ . is defined as the enthaly change for the formation of one mole of substance from its constituent elements in their standard states. Thus, elements n their standard states have Δ1, Heat of formation values can be used to calculate the enthalpy change of any reaction For which of the following reactions s Δ1 in equal to Δ1 of the pro uctismou do not need to look up any vales to answer this question Check all that apply MasteringChemistry: HW6-Google Chrome- o Li(s) + (1)→LiF(s) Consider, for example, the reaction 슐 https://session.masteringchemistry.com/myct/itemView?mode-myA命a H202(g)2(g)H20(g) H2 (g) + O2 (g)→H2O (g) 2NO(g)02(2NO2(E) ers with hest of formation values given by the following table: ANSWER 1 Substance kJ/mol NO(g) | 90.2 02Li(s),F2(g) )2LiF(s) 0 Li(s) F2 (g) →LiF(s) H2O2 (g)-,02 (g) + H2O(g) Submit Hints MyAnswers Give Up Review Part NO2(g) 332 Incorrect; One attempt remaining; Try Again Li(s) + '2(g)→LiF(s) Then the heat of formation for the overall reaction is Part B Δ Inn Δ (products) Δ (reactants) [2(90.2)0] 2(33.2) The combustion of heptane, CH1s.occurs via the reaction Look again at the coefficients in the reactions. The heat of formation is defined by a reaction that forms one mole of product. 114 kJ/mol Calcuiste the molar enthalpy for the combustion of heptane. Use the hest of ANSWER 2 Li(s) F2 (1)→ LiF(s) H2O2 (g)- O2(g) + H2O(g) H2 (g) 02 (g) →H2O(g) Express your answer to four significant figures and include the The acceptable margin of error for this question is 1%, so use all digit 2Li(s)+ Fa() 2LiF(s) Li(s)--P, (g)→LiF(s) Hints MyAnswers Give Up Review Part Correct Look again t the coefficients in the resctions. The heat of formation is defined by a resction that forms one mole of product. ntinue

Question 5 (12 Marks) Let P be differentiable on R, one version of Rolle's theorem states "between the zeros of F there is a zero of F. a) Verify this theorem for the polynomials Fi = (x-1)(z-2) F2 = (z-1)(z-2)(z-3), by finding the zeros of both F and F. b) Now suppose that F is differentiable on R. Write down a one line statement in which Rolle's theorem is applied to F', and verify your new theorem for F2. c) Let G = x" +ax + b, where n is a positive integer and a and b are non-zero real constants. Make use of part (a) to prove that: (i) if n is even then G has at most two zeros, (ii) if n is odd then G has at most three zeros