A 0.8743 g sample of KHP was titrated 42.45-mL of NaOH solution until the phenolphthalein endpoint. What is the molarity of the NaOH solution?
42.45-mL=0.04245L
0.8743 g sample of KHP*(1 mol/204.22 g)= moles of KHP
moles of KHP=moles of NaOH
Molarity (M)=moles of NaOH/0.04245L
**Answer contains 4-significant figures
.1007
To find the molarity of the NaOH solution, we can use the formula:
Molarity (M) = (moles of solute) / (volume of solution in liters)
First, let's calculate the moles of KHP using its molar mass.
Molar mass of KHP = (39.10 g/mol) + (1.01 g/mol) + (16.00 g/mol) + (1.01 g/mol) + (2 * 1.01 g/mol) = 204.23 g/mol
The number of moles of KHP can be calculated using the mass and molar mass:
moles of KHP = mass of KHP / molar mass of KHP
= 0.8743 g / 204.23 g/mol
≈ 0.004281 mol
Since the balanced equation for the reaction is:
NaOH + KHP -> NaKP + H2O
We know that the ratio of moles of NaOH to KHP is 1:1.
Therefore, the number of moles of NaOH is also approximately 0.004281 mol.
Next, we need to convert the volume of the NaOH solution from milliliters to liters:
volume of NaOH solution = 42.45 mL = 42.45 mL * (1 L/1000 mL) = 0.04245 L
Now, we can use the formula to find the molarity of the NaOH solution:
Molarity = moles of NaOH / volume of NaOH solution
= 0.004281 mol / 0.04245 L
≈ 0.1008 M
Therefore, the molarity of the NaOH solution is approximately 0.1008 M.
To find the molarity of the NaOH solution, we need to use the balanced equation for the reaction between KHP (potassium hydrogen phthalate) and NaOH.
The balanced equation for the reaction is:
KHP + NaOH -> NaKP + H2O
From the balanced equation, we can see that the reaction is a 1:1 ratio between KHP and NaOH. This means that one mole of KHP reacts with one mole of NaOH.
Step 1: Convert the mass of KHP to moles.
Given that the sample of KHP has a mass of 0.8743 g, we need to convert this to moles. To do this, we divide the mass by the molar mass of KHP.
The molar mass of KHP can be calculated using the periodic table and the formula KHP, which is C8H5KO4.
The molar mass of K is 39.1 g/mol, H is 1.0 g/mol, C is 12.01 g/mol, and O is 16.0 g/mol.
Molar mass of KHP = (8 × C) + (5 × H) + K + (4 × O)
Molar mass of KHP = (8 × 12.01 g/mol) + (5 × 1.0 g/mol) + 39.1 g/mol + (4 × 16.0 g/mol)
Molar mass of KHP = 204.22 g/mol
Now we can calculate the number of moles of KHP:
Number of moles = mass / molar mass
Number of moles = 0.8743 g / 204.22 g/mol
Number of moles ≈ 0.00428 mol
Step 2: Calculate the molarity of NaOH solution.
The molarity (M) of a solution is defined as moles of solute divided by volume of solvent (in liters). In this case, the solute is NaOH and the solvent is water.
Given that the volume of NaOH solution used is 42.45 mL (or 0.04245 L), we can use the equation:
Molarity = moles of solute / volume of solvent (in liters)
Molarity = 0.00428 mol / 0.04245 L
Molarity ≈ 0.101 M
Therefore, the molarity of the NaOH solution is approximately 0.101 M.