Calculate the pH of concentrated hydrochloric acid if this solution is 24.8 % HCl by weight and has a density of 1.16 g/mL.
a. ) -0.77
b. ) -0.83
c. ) -0.90
d. ) -0.98
e. ) -1.01
i got c) by converting density into concentration (mol/L) and then, multiplying by 0.248. next, i took the negative log of the concentration to find pH.
is that how u would solve the problem?
Yes, your procedure as well as the answer is correct.
Well, it seems like you've got the right idea, but let me add a little humor into the mix while explaining the solution.
To solve this problem, you first need to convert the density into concentration, just like you did. However, be careful not to get too dense while doing the calculations.
Once you have the concentration in moles per liter (mol/L), multiply it by 0.248 to find the concentration of HCl in your solution. Don't worry, I won't multiply that by any clown-sized shoes.
Now comes the funny part. Take the negative log of the concentration to find the pH. It's like telling a sad chemistry joke and hearing a reaction of laughter.
So, after all the math is done, you'll find that the pH of this concentrated hydrochloric acid solution is option c) -0.90. Congratulations, you've successfully solved the problem without clowning around too much!
Yes, you are on the right track! To solve this problem, you need to convert the given concentration by weight (24.8% HCl) into molarity (mol/L) using the density.
Here are the step-by-step calculations:
1. Calculate the molar mass of HCl:
- Molar mass of H = 1.00784 g/mol
- Molar mass of Cl = 35.453 g/mol
- Molar mass of HCl = Molar mass of H + Molar mass of Cl = 1.00784 g/mol + 35.453 g/mol = 36.46084 g/mol
2. Calculate the moles of HCl:
- Given concentration = 24.8% HCl by weight
- Mass of 100 g of solution = 100 g
- Mass of HCl in 100 g of solution = 24.8 g (since it is 24.8% HCl)
- Moles of HCl = mass of HCl / molar mass of HCl = 24.8 g / 36.46084 g/mol = 0.679 mol
3. Calculate the volume of the solution:
- Given density = 1.16 g/mL
- Mass of the solution = 100 g (from step 2)
- Volume of the solution = mass of the solution / density = 100 g / 1.16 g/mL = 86.207 mL = 0.086207 L
4. Calculate the concentration of HCl in the solution:
- Concentration (C) = moles of solute / volume of solution
- Concentration (C) = 0.679 mol / 0.086207 L = 7.879 mol/L
5. Calculate the pH:
- pH = -log(C)
- pH = -log(7.879)
- pH ≈ -0.90
So, the pH of the concentrated hydrochloric acid solution is approximately -0.90.
Therefore, the correct answer is c) -0.90.
Yes, your approach to solving the problem is correct. To calculate the pH of the concentrated hydrochloric acid solution, you need to convert the given density into concentration (in mol/L) and then find the negative logarithm of the concentration to determine the pH.
Here's a step-by-step explanation of how to solve the problem:
Step 1: Calculate the molar mass of hydrochloric acid (HCl).
The molar mass of HCl is the sum of the atomic masses of hydrogen (H) and chlorine (Cl). The atomic mass of hydrogen is approximately 1.01 g/mol, and the atomic mass of chlorine is approximately 35.45 g/mol. Thus, the molar mass of HCl is 1.01 + 35.45 = 36.46 g/mol.
Step 2: Convert the given density to concentration (in mol/L).
The given density of 1.16 g/mL can be converted to grams per liter (g/L) by multiplying by 1000 since there are 1000 mL in a liter. Therefore, the concentration of HCl is (1.16 g/mL) * (1000 mL/L) = 1160 g/L.
Next, convert the concentration from grams to moles. Divide the concentration in grams by the molar mass of HCl to obtain the concentration in moles per liter. The concentration in moles per liter is (1160 g/L) / (36.46 g/mol) = 31.83 mol/L.
Step 3: Calculate the pH.
To calculate the pH, take the negative logarithm (base 10) of the concentration. In this case, pH = -log(31.83) = -0.90.
Therefore, the correct answer is c) -0.90.
Great job on solving the problem using conversion and the logarithmic relationship between concentration and pH!