Methanol (CH3OH) is used as a fuel in race cars. |
Part A Write a balanced equation for the combustion of liquid methanol in air, assuming H2O(g) as a product. Express your answer as a chemical equation. Identify all of the phases in your answer.
SubmitPrevious AnswersRequest Answer Incorrect; Try Again; 5 attempts remaining Part B Calculate the standard enthalpy change for the combustion of 1 mol of liquid methanol, assuming H2O(g) as a product. Express your answer using four significant figures.
SubmitRequest Answer Part C Calculate the heat produced by combustion per liter of methanol. Methanol has a density of 0.791 g/mL. Express your answer using three significant figures.
SubmitRequest Answer Part D Calculate the mass of CO2 produced per kJ of heat emitted. Express your answer using four significant figures.
|
Answer – Part A ) We are given methanol and we need to write the balanced combustion reaction equation
2 CH3OH (l) + 3 O2(g) -----> 2 CO2(g) + 4 H2O(g)
Part B) We know standard enthalpy formula
We know,
ΔHorxn = ∑ ΔHof of product – ∑ ΔHof of reactant
= [ (2* ΔHof CO2(g)) + (4* ΔHof H2O(g) )] – [ 2*ΔHof CH3OH (l) + 3 *ΔHof O2(g) ]
= (2*-393.51 + 4*-241.82) - ( 2*-239.03 + 3*0.00)
= -1276 kJ
This is for 2 moles of CH3OH, so for 1 mole of CH3OH = -1276 /2 = -638.1 kJ
Part C) We are given, density of methanol = 0.791 g/mL
volume of methanol = 1 L = 1000 mL
we need to calculate the moles of methanol
mass of methanol = density x volume
= 0.791 g/mL x 1000 mL
= 791 g
moles of methanol = 791g / 32.04 g.mol-1
= 24.68 moles
From the above reaction
2 moles of CH3OH = -1276.24 kJ
so, 24.68 moles of CH3OH = ? kJ
= -1.57 x104 kJ/L
Part D) From the first reaction
-1276 kJ = 2 moles of CO2
-1 kJ = ? moles of CO2
= 0.00157 moles of CO2
Mass of CO2 = 0.00157 moles x 44 g/mol
= 0.06895 g of CO2
Methanol (CH3OH) is used as a fuel in race cars. Part A Write a balanced equation...
Hydrogen and methanol have both been proposed as alternatives to hydrocarbon fuels. Part A Write balanced reactions for the complete combustion of hydrogen. Express your answer as a chemical equation. Identify all of the phases in your answer. 2H2 (8)+O2(g)+2H2O(1) Submit Previous Answers Request Answer * Incorrect; Try Again Part B Use standard enthalpies of formation to calculate the amount of heat released per kilogram of the fuel. Express your answer using four significant figures. DAXO amount of heat released...
Describe how to prepare each solution from the dry solute and the solvent. Part A Part complete How much dry solute would you take to prepare 135 mL of 0.100 M NaNO3 ? Express your answer using three significant figures. -- Part B Part complete How much dry solute would you take to prepare123 g of 0.120 m NaNO3 ? Express your answer using three significant figures. -- msolute m s o l u t e = nothing gNaNO3 Part...
You may want to reference (Pages 291 - 293) Section 8.6 while completing this problem. Use the molar volume to calculate each of the following at STP. Part A Part complete Calculate the number of moles of CO2 in 4.10 L of CO2 gas. Express your answer to three significant figures and include the appropriate units. -- SubmitPrevious AnswersRequest Answer Part B Part complete Calculate the volume, in liters, occupied by 0.140 mol of He gas. Express your answer to...
Part A Part complete Calculate [H3O+] in the following aqueous solution at 25 ∘C : [OH−]= 5.3×10−4 M . Express your answer using two significant figures. -- SubmitPrevious AnswersRequest Answer Part B Part complete Calculate [H3O+] in the following aqueous solution at 25 ∘C : [OH−]= 2.4×10−12 M . Express your answer using two significant figures. -- [H3O+] [ H 3 O + ] = nothing M SubmitPrevious AnswersRequest Answer Part C Part complete Calculate [H3O+] in the following aqueous...
Part B Part complete ΔH∘rxn=+ 83 kJ , ΔSrxn=+ 146 J/K , T= 759 K Express your answer as an integer. -- SubmitPrevious AnswersRequest Answer Part C Part complete ΔH∘rxn=+ 83 kJ , ΔSrxn=− 146 J/K , T= 309 K Express your answer as an integer. -- ΔG Δ G = nothing kJ SubmitPrevious AnswersRequest Answer Part D Part complete ΔH∘rxn=− 83 kJ , ΔSrxn=+ 146 J/K , T= 407 K Express your answer as an integer. -- ΔG Δ...
The following data show the rate constant of a reaction measured at several different temperatures. Temperature (K) Rate Constant (1/s) 300 1.19×10−2 310 3.64×10−2 320 0.104 330 0.278 340 0.703 Part A Part complete Use an Arrhenius plot to determine the activation barrier for the reaction. Express your answer using three significant figures. -- SubmitPrevious AnswersRequest Answer Part B Part complete Use an Arrhenius plot to determine frequency factor for the reaction. Express your answer using two significant figures. --...
The acid-dissociation constant for benzoic acid (C6H5COOH) is 6.3×10−5. Calculate the equilibrium concentration of H3O+ in the solution if the initial concentration of C6H5COOH is 0.065 M . Express your answer using two significant figures. TemplatesSymbols undoredoresetkeyboard shortcutshelp [H3O+] [ H 3 O + ] = M SubmitPrevious AnswersRequest Answer Incorrect; Try Again; 5 attempts remaining Part B Calculate the equilibrium concentration of C6H5COO− in the solution if the initial concentration of C6H5COOH is 0.065 M . Express your answer...
Constants | Periodic Table Styrene (C8H8), the precursor of polystyrene polymers, has a standard heat of combustion of -4395 kJ/mol.(Figure 1) Part A Write a balanced equation for the combustion reaction. Express your answer as a chemical equation. Identify all of the phases in your answer. Phases (states) should be entered in lowercase. No credit lost. Try again. Previous AnswersRequest Answer Part B CalculateΔH∘f for styrene in kJ/mol. ΔH∘f[CO2(g)]=−393.5kJ/mol; ΔH∘f[H2O(l)]=−285.8kJ/mol Express your answer using three significant figures. ΔH∘f Δ H...
9. Certain race cars use methanol (CH3OH; also called wood alcohol) as a fuel. Methanol has a molecular mass of 32.0 g/mol and a density of 0.79 g/mL. The combustion of methanol occurs according to the following equation: 2CH3OH + 3O2 ? 2CO2 + 4H2O In a particular reaction 2.00 L of methanol are reacted with 80.0 kg of oxygen. a. What is the limiting reactant? b. What reactant and how many grams of it are left over? c. How...
Learning Goal: To learn how to use the Nernst equation. The standard reduction potentials listed in any reference table are only valid at standard-state conditions of 25 ∘C and 1 M . To calculate the cell potential at non-standard-state conditions, one uses the Nernst equation, E=E∘−2.303RTnFlog10Q where E is the potential in volts, E∘ is the standard potential in volts, R=8.314J/(K⋅mol) is the gas constant, T is the temperature in kelvins, n is the number of moles of electrons transferred,...