CH4+Cl2 -> CH2Cl2+HCl if 6.00 g of CH4 are mixed with 6.00 g of Cl2, how much HCl can be made? What is the percent yield if 2.5 g are recovered from the reaction?
1. Balance the equation.
2a. Convert 6.0 g CH4 to moles. moles = grams/molar mass.
2b. Convert 6.0 g Cl2 to moles. same procedure.
3a. Using the coefficients in the balanced equation, convert moles CH4 to moles HCl.
3b. Same procedure but convert moles Cl2 to moles HCl.
3c. It is quite likely that the answers from 3a and 3b will be different which means one of them is wrong. The correct one, in limiting reagent problems, is ALWAYS the smaller value and the reagent producing that number is the limiting reagent.
4. Convert moles HCl to grams. g = moles x molar mass. This is the theoretical yield
5. %yield = (actual yield/theoretical yield)*100 = ??
actual yield is given in the problem as 2.5 g.
To determine the amount of HCl that can be made, we need to find the limiting reactant in the reaction. The limiting reactant is the reactant that is completely consumed first, thus limiting the amount of product that can be formed.
1. Calculate the moles of CH4:
The molar mass of CH4 (methane) is:
12.01 g/mol (C) + 1.01 g/mol (4xH) = 16.05 g/mol
The moles of CH4 can be calculated using the formula: moles = mass / molar mass.
moles of CH4 = 6.00 g / 16.05 g/mol
2. Calculate the moles of Cl2:
The molar mass of Cl2 is:
35.45 g/mol (2xCl) = 70.90 g/mol
The moles of Cl2 can be calculated using the same formula from step 1:
moles of Cl2 = 6.00 g / 70.90 g/mol
3. Determine the stoichiometric ratio:
From the balanced equation, we can see that for every mole of CH4 reacted, 1 mole of HCl is produced. This means the ratio of moles of HCl to moles of CH4 is 1:1.
4. Identify the limiting reactant:
To find the limiting reactant, compare the moles of CH4 to the moles of Cl2. The reactant that produces fewer moles of HCl is the limiting reactant.
Since the moles of HCl produced are the same as the moles of CH4 present, the moles of HCl that can be made are equal to the moles of CH4 calculated in step 1.
5. Calculate the mass of HCl produced:
To determine the mass of HCl, we need to use the formula: mass = moles × molar mass.
The molar mass of HCl is:
1.01 g/mol (H) + 35.45 g/mol (Cl) = 36.46 g/mol
The mass of HCl produced can be calculated as:
mass of HCl = moles of HCl × molar mass
6. Calculate the percent yield:
To calculate the percent yield, divide the actual yield (recovered mass of HCl) by the theoretical yield (mass of HCl calculated in step 5) and multiply by 100%.
percent yield = (actual yield / theoretical yield) × 100%
Using the given information that 2.5 g of HCl are recovered, we can calculate the percent yield using the formula above.
Please note that the balanced equation you provided is incorrect. The correct equation for the reaction between CH4 and Cl2 to form CH2Cl2 and HCl is:
CH4 + Cl2 -> CH2Cl2 + HCl