Consider the reaction between 60.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 28.0 L of O2 at 27.0°C and a pressure of 1.51 atm?
I am unsure of where to start with this problem...
I don't see a question here.
sorry, I get distracted easily:
Consider the reaction between 60.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 28.0 L of O2 at 27.0°C and a pressure of 1.51 atm. The products of the reaction are CO2(g) and H2O(g).
Calculate the number of moles of H2O formed if the reaction goes to completion.
You have a number of problems here all rolled into one giant problem. First it is a limiting reagent (LR) problem.
Convert ethanol to grams using the density. mass = volume x density.
Then convert g ethanol to mols. mols = grams/molar mass
Convert O2 to mols using PV = nRT and remember T must be in kelvin.
Using the coefficients in the balanced equation, convert mols ethanol to mols H2O.
Do the same for mols O2 to mols H2O.
It is likely that the two values for mol H2O will not agree which means one of them is wrong. The correct value in limiting reagent problems is ALWAYS the smaller value and the reagent producing that value is the limiting reagent.
Ok so I was making it harder than I thought and should have followed my instinct when my brain kept saying limiting reactant.
Im gonna get it done then, last problem on homework.
Thank You Dr. Bob
To solve this problem, you can follow these steps:
1. Convert the volume of ethanol from milliliters to grams:
Given: 60.0 mL
Density of ethanol: 0.789 g/mL
Calculation: 60.0 mL x 0.789 g/mL = 47.34 g
2. Convert the volume of O2 from liters to moles:
Given: 28.0 L
Calculation: To convert from liters to moles, you need to use the ideal gas law.
The ideal gas law is expressed as PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
In this case, you are given the pressure (1.51 atm), volume (28.0 L), and temperature (27.0°C), so you can solve for the number of moles (n).
First, convert the temperature from Celsius to Kelvin by adding 273.15:
Temperature (T) = 27.0°C + 273.15 = 300.15 K
Now, rearrange the ideal gas law equation to solve for n:
n = (PV) / (RT)
n = (1.51 atm x 28.0 L) / (0.0821 L·atm/mol·K x 300.15 K)
Calculation: n = 1.51 x 28.0 / (0.0821 x 300.15) = 1.85 moles
3. Use the balanced chemical equation to determine the mole ratio between ethanol and O2 in the reaction.
The balanced chemical equation for the reaction between ethanol (C2H5OH) and O2 is:
C2H5OH + 3O2 -> 2CO2 + 3H2O
According to the equation, 1 mole of ethanol reacts with 3 moles of O2.
4. Calculate the amount of O2 needed to react with the given amount of ethanol.
The molar ratio between ethanol and O2 is 1:3, meaning that for every mole of ethanol, 3 moles of O2 are required.
Given the number of moles of ethanol as 1.85, you can multiply it by the molar ratio (3) to calculate the moles of O2 required:
Moles of O2 = 1.85 moles ethanol x 3 moles O2 / 1 mole ethanol
Calculation: Moles of O2 = 1.85 moles x 3 = 5.55 moles
Now you have calculated the moles of ethanol and moles of O2 required for the reaction.