4.82 mL of a 0.262 M NaOH solution reacts completly with 4.79 mL of HCl solution according to the balanced chemical reaction shown below:
HCl (aq) + NaOH (aq) -> NaCl*aq) + H2O (I)
What is the molarity of the HCl solution?
4.82 x (1L/1000 mL) = .00482L
4.79 x (1L/1000 mL) = .00479L
(.00482L)(0.262M) = .00126284
(.00126284M/.00479L) = .263 M HCl
I was wondering if I set up and solved this problem correctly?
The set up looks ok. I don't think you rounded properly. I get 0.26364 M which I would round to 0.264 M.
By the way, just as a shortcut, when everything is listed in mL, you need not change everything to L.
Ml x M = mL x M.
L x M = moles
mL x M = millimoles.
Yes, you set up and solved the problem correctly. Let's go through the steps to verify:
1. Convert the given volumes of solutions to liters:
4.82 mL = 0.00482 L
4.79 mL = 0.00479 L
2. Calculate the moles of NaOH using its molarity and volume:
moles of NaOH = molarity of NaOH x volume of NaOH = 0.262 M x 0.00482 L = 0.00126284 mol
3. Since the balanced equation tells us that the mole ratio of NaOH to HCl is 1:1, the moles of HCl will also be 0.00126284 mol.
4. Finally, calculate the molarity of HCl using the moles of HCl and the volume of HCl:
molarity of HCl = moles of HCl / volume of HCl = 0.00126284 mol / 0.00479 L ≈ 0.263 M
Therefore, the molarity of the HCl solution is approximately 0.263 M. Well done!