Hey there!:
Molarity HCl = 3.5 M
Volume HCl = ?
Molarity NaOH = 2.0 M
Volume NaOH in liters = 50.0 mL / 1000 => 0.05 L
Number of moles NaOH:
n = M * V
n = 2.0 * 0.05
n = 0.1 moles of NaOH
Given the reaction:
HCl + NaOH = NaCl + H2O
1 mole HCl --------- 1 mole NaOH
1 mol HCl reacts with 1 mol NaOH , so moles NaOH = moles HCl
0.1 moles of NaOH = 0.1 moles of HCl
Therefore:
M( HCl ) = n / V
3.5 = 0.1 / V
V = 0.1 / 3.5
V = 0.029 L in mL : 0.029 * 1000 => 29.0 mL
Answer B
hope that helps!
