Consider the reaction
Mg +2HCl ------>MgCl2 + H2
What is the minimum amount of 1.85M HCl is necessary to produce 28.5L of H2 at STP
Please help me work this problem
Well, well, well, it seems like we've got ourselves a stoichiometry problem here. Don't worry, I'll do my best to make it an entertaining experience for you.
First things first, let's write down the balanced equation to remind ourselves what's happening in this reaction:
Mg + 2HCl → MgCl2 + H2
Now, let's break it down step by step. We want to find the minimum amount of 1.85M HCl needed to produce 28.5L of H2 at STP. Here's what we know:
Molarity of HCl = 1.85M
Volume of H2 = 28.5L
To start, we need to convert the volume of H2 at STP (Standard Temperature and Pressure) to moles. Remember, at STP, 1 mole of any gas occupies 22.4L of space. So, we have:
28.5L H2 * (1 mole H2 / 22.4L H2) = 1.27 moles H2
Now, looking at the balanced equation, we can see that 2 moles of HCl react to produce 1 mole of H2. Therefore, we need twice the moles of HCl compared to the H2 moles. That means we need 2.54 moles of HCl.
Now, let's find the amount of HCl in liters. We can use the definition of molarity (moles of solute / liters of solution). Rearranging the equation, we have:
1.85M = 2.54 moles HCl / x liters HCl
Solving for x (liters of HCl), we get:
x = 2.54 moles HCl / 1.85M
x ≈ 1.37L of HCl
So, the minimum amount of 1.85M HCl necessary to produce 28.5L of H2 at STP is approximately 1.37 liters.
And there you have it! Problem solved, with a sprinkle of humor along the way. Keep that clown nose high, my friend!
To determine the minimum amount of 1.85M HCl required to produce 28.5L of H2 at STP, you will need to use stoichiometry and the balanced chemical equation for the reaction.
Step 1: Write the balanced chemical equation for the reaction:
Mg + 2HCl → MgCl2 + H2
Step 2: Convert 28.5L of H2 to moles using the ideal gas law at STP:
1 mole of any gas at STP occupies 22.4L, so:
28.5 L H2 * (1 mole H2 / 22.4 L) = 1.27 moles H2
Step 3: Use the stoichiometry of the balanced chemical equation to find the moles of HCl required.
From the balanced equation, it is clear that 1 mole of Mg reacts with 2 moles of HCl to produce 1 mole of H2.
Therefore, to produce 1.27 moles of H2, we will need (1.27 moles H2)*(2 moles HCl / 1 mole H2) = 2.54 moles of HCl.
Step 4: Convert moles of HCl needed to volume using the given concentration of HCl.
We know that the concentration of HCl is 1.85 mol/L.
Using the formula:
Volume = Moles / Concentration
Volume = 2.54 moles HCl / 1.85 mol/L = 1.37 L
Therefore, the minimum amount of 1.85M HCl necessary to produce 28.5L of H2 at STP is 1.37L.
To determine the minimum amount of 1.85M HCl needed to produce 28.5L of H2 at STP, we can use stoichiometry and the given balanced equation.
The balanced equation for the reaction is:
Mg + 2HCl → MgCl2 + H2
From the balanced equation, we can see that 2 moles of HCl are required to produce 1 mole of H2.
To find the minimum amount of HCl needed, we need to calculate the moles of H2 produced using the ideal gas law equation:
PV = nRT
Where:
P = pressure (STP = 1 atm)
V = volume (28.5L)
n = number of moles (unknown)
R = ideal gas constant (0.0821 L*atm/(mol*K))
T = temperature (STP = 273.15 K)
Rearranging the equation to solve for moles (n), we get:
n = PV /RT
Substituting the given values, we have:
n = (1 atm * 28.5L) / (0.0821 L*atm/(mol*K) * 273.15 K)
Now, let's calculate the moles of HCl required using stoichiometry.
From the balanced equation, we know that 2 moles of HCl are needed to produce 1 mole of H2.
So, the moles of HCl required to produce the calculated moles of H2 will be:
moles of HCl = (2 moles HCl / 1 mole H2) * calculated moles of H2
Finally, we can determine the minimum amount of 1.85M HCl needed.
To calculate this, we need to convert the moles of HCl to the volume using the molarity formula:
Molarity (M) = moles / volume (in liters)
Rearranging the formula to solve for volume, we get:
Volume (in liters) = moles / Molarity (in M)
Substituting the values, we can calculate the minimum volume of 1.85M HCl needed.
I hope these explanations help you work through the problem.
You know a mole of a gas at STP occupies 22.4 L.
moles H2 produced = 28.5L/22.4 L/mol = ??
Use the coefficients in the balanced equation to convert moles H2 to moles HCl.
Then MHCl = moles HCl/L HCl. You have M HCl and moles HCl, solve for L and convert to mL.