How many mL of .150 M sodium hydroxide is required to neutralize 25 mL of .125 M of phosphoric acid?
How many mL of a .10 M NaOH solution are needed to neutralize 15 mL of .20 M H3PO4 solution?
Write nbalanced equation:
3NaOH + H3PO4 → Na3PO4 + 3H2O
3mol NaOH recat with 1mol H3PO4
In all these titration questions, do it the simple way: Use the following equation:
Ma*Va/na = Mb*Vb/nb
Where:
Ma = molarity of acid
Va = volume of acid
na = number of moles acid used, from the balanced equation
Mb = molarity of base
Vb = volume of base
nb = number of moles of base used, from the balanced equation:
substitute:
0.20*15/1 = 0.10*Vb/3
Vb = 0.20*15*3 /0.10
Vb = 90ml
The correct answer is : volume of 0.10NaOH required = 90ml.
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Similar problem, different concentrations, volumes, etc.
Just try it yourself! :)
To determine the amount of sodium hydroxide needed to neutralize phosphoric acid, we can use the balanced chemical equation between the two compounds:
H3PO4 + 3NaOH -> Na3PO4 + 3H2O
From the balanced equation, we can see that one mole of phosphoric acid (H3PO4) reacts with three moles of sodium hydroxide (NaOH) to produce one mole of sodium phosphate (Na3PO4) and three moles of water (H2O).
First, let's determine the number of moles of phosphoric acid in 25 mL of a 0.125 M solution. We have:
Moles of H3PO4 = concentration (M) × volume (L)
= 0.125 mol/L × 0.025 L
= 0.003125 mol
Since the stoichiometry of the reaction tells us that three moles of NaOH react with one mole of H3PO4, we can determine the number of moles of NaOH required to neutralize this amount of H3PO4:
Moles of NaOH = 3 × moles of H3PO4
= 3 × 0.003125 mol
= 0.009375 mol
Lastly, we need to convert the moles of NaOH into milliliters (mL) of a 0.150 M solution. Using the equation:
Moles of NaOH = concentration (M) × volume (L)
We can solve for the volume:
Volume (L) = moles of NaOH / concentration (M)
= 0.009375 mol / 0.150 mol/L
= 0.0625 L
Now, we can convert the volume from liters to milliliters:
Volume (mL) = 0.0625 L × 1000 mL/L
= 62.5 mL
Therefore, 62.5 mL of a 0.150 M sodium hydroxide solution is required to neutralize 25 mL of a 0.125 M phosphoric acid solution.