"Calculate the ph of the resulting solution if 31.0 mL of 0.310 M HCl is added to 21.0 mL of 0.410 M NaOH".
I've tried getting this problem several times and can't come up with the right answer. Please help!
I've tried getting this problem several times and can't come up with the right answer. Please help!
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HCl reacts with NaOH to produce a neutral salt NaCl.
The equation:
HCl + NaOH → NaCl + H2O
1mol HCl will react with 1 mol NaOH
Mol HCl in 31.0mL of 0.310M solution = 31/1000*0.31 = 0.00961 mol HCl
Mol NaOH in 21mL of 0.410M solution = 21/1000*0.41 = 0.00861 mol NaOH
When you mix these , the 0.00861 mol NaOH reacts with 0.0861 mol HCl , and 0.0010 mol HCl remains unreacted
You then have 0.0010mol HCl dissolved on 31+21= 52mL of solution
Molarity of HCl solution = 0.001/0.052 = 0.0192M solution
Because HCl is a strong acid , [H+] = [HCl] = 0.0192M
pH = -log [H+]
pH = -log 0.0192
pH = 1.72
The equation:
HCl + NaOH → NaCl + H2O
1mol HCl will react with 1 mol NaOH
Mol HCl in 31.0mL of 0.310M solution = 31/1000*0.31 = 0.00961 mol HCl
Mol NaOH in 21mL of 0.410M solution = 21/1000*0.41 = 0.00861 mol NaOH
When you mix these , the 0.00861 mol NaOH reacts with 0.0861 mol HCl , and 0.0010 mol HCl remains unreacted
You then have 0.0010mol HCl dissolved on 31+21= 52mL of solution
Molarity of HCl solution = 0.001/0.052 = 0.0192M solution
Because HCl is a strong acid , [H+] = [HCl] = 0.0192M
pH = -log [H+]
pH = -log 0.0192
pH = 1.72