A)What volume of 0.145 M HClO4 solution is needed to neutralize 46.00 mL of 8.75×10−2 M NaOH?
B)What volume of 0.138 M HCl is needed to neutralize 2.79 g of Mg(OH)2?
HClO4 + NaOH = NaClO4 + H2O
How many moles of NaOH do you have?
0.046L * 8.75*10^-2 moles/L = 0.004025 moles
So, you will need that many moles of HClO4
0.004025 mol * 1000mL/0.145mol = 27.758 mL of HClO4
do the other the same way
To answer these questions, we can use the concept of stoichiometry and the balanced chemical equations of the reactions involved.
A) To neutralize NaOH with HClO4, the balanced chemical equation is:
HClO4(aq) + NaOH(aq) -> NaClO4(aq) + H2O(l)
From the balanced equation, we can see that the mole ratio of HClO4 to NaOH is 1:1. This means that it takes one mole of HClO4 to neutralize one mole of NaOH.
Step 1: Calculate the moles of NaOH using its concentration and volume:
moles of NaOH = concentration * volume
moles = (8.75 x 10^-2 M) * (46.00 mL) * (1 L /1000 mL)
Step 2: Use the mole ratio to find the moles of HClO4 needed:
moles of HClO4 = moles of NaOH
Step 3: Finally, calculate the volume of HClO4 solution required using its concentration and moles obtained:
volume of HClO4 = moles / concentration
Therefore, the volume of 0.145 M HClO4 solution needed to neutralize 46.00 mL of 8.75×10^−2 M NaOH is determined by the above calculations.
B) To neutralize Mg(OH)2 with HCl, the balanced chemical equation is:
2 HCl(aq) + Mg(OH)2(aq) -> MgCl2(aq) + 2 H2O(l)
From the balanced equation, we can see that the mole ratio of HCl to Mg(OH)2 is 2:1. This means that it takes two moles of HCl to neutralize one mole of Mg(OH)2.
Step 1: Calculate the moles of Mg(OH)2 using its molar mass and mass given:
moles of Mg(OH)2 = mass / molar mass
moles = 2.79 g / molar mass of Mg(OH)2
Step 2: Use the mole ratio to find the moles of HCl needed:
moles of HCl = 2 * moles of Mg(OH)2
Step 3: Finally, calculate the volume of HCl solution required using its concentration and moles obtained:
volume of HCl = moles / concentration
Therefore, the volume of 0.138 M HCl solution needed to neutralize 2.79 g of Mg(OH)2 is determined by the above calculations.