If 14.50mL of 0.25M sodium hydroxide reacts completely with 25.0 mL of hydrochloric acid, what is the concentration of the hydrochloric acid?
NaOH + HCl ==> NaCl + H2O
mols NaOH = M x L = ?
mols HCl = mols NaOH since the equation tells you 1 mol NaOH = 1 mol HCl.
Then M HCl = mols HCl/L HCl = ?
To find the concentration of the hydrochloric acid, we will use the concept of stoichiometry. The balanced chemical equation for the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is:
HCl + NaOH -> NaCl + H2O
From the equation, we can see that the ratio between HCl and NaOH is 1:1. This means that for every one mole of HCl, we need one mole of NaOH to react completely.
First, let's convert the volume of NaOH solution (14.50 mL) to moles. To do this, we need to know the molar mass of NaOH, which is:
Na (sodium) = 22.99 g/mol
O (oxygen) = 16.00 g/mol
H (hydrogen) = 1.01 g/mol
Na + O + H = 22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 40.00 g/mol
Now we can find the number of moles of NaOH by dividing the given volume (in mL) by the molar volume (in L/mol) and multiplying by the molarity (in mol/L):
moles of NaOH = (14.50 mL / 1000 mL/L) * 0.25 mol/L
Next, since the stoichiometry of the reaction is 1:1, the moles of HCl must be the same as the moles of NaOH. Therefore, the moles of HCl are also:
moles of HCl = (14.50 mL / 1000 mL/L) * 0.25 mol/L
Finally, to find the concentration of HCl, we need to convert the moles of HCl to a molarity (concentration) by dividing by the volume of HCl solution (25.0 mL) and multiplying by 1000 to convert mL to L:
concentration of HCl = (moles of HCl / 25.0 mL) * 1000 mL/L
By performing these calculations, you can determine the concentration of the hydrochloric acid.