A student uses (2.1000x10^-1) grams of oxalic acid dihydrate. Her titration required (2.63x10^1) mL of NaOH to reach the endpoint. What is the M of her NaOH solution. Put in scientific notation w/ 3 sig figs.
How would you do this through dimensional analysis?
Am I missing a part? As I worked it out, I'm getting 2.11x10^-4...
I'm not sure if this is right?
That isn't right.
Write the equation and balance it.
Convert g H2C2O4 to mols. mol = g/molar mass = ?
Convert mols H2C2O4 to mols NaOH.
M NaOH = mols NaOH/L NaOH = ?
Post your work if you get stuck.
To find the molarity (M) of the NaOH solution, you can use the concept of dimensional analysis. Here's how you can approach this problem step by step:
1. Start by converting the given quantity of oxalic acid dihydrate into moles. This can be done using the molar mass of oxalic acid dihydrate (H2C2O4.2H2O), which is calculated as follows:
Molar mass of H2C2O4 = (2*1.01 g/mol) + (2*12.01 g/mol) + (4*16.00 g/mol) = 90.04 g/mol
Molar mass of H2O = (2*1.01 g/mol) + (4*16.00 g/mol) = 18.02 g/mol
Therefore, the molar mass of H2C2O4.2H2O = (90.04 g/mol) + (2 * 18.02 g/mol) = 126.08 g/mol
Now, convert the given mass of oxalic acid dihydrate (2.1000x10^-1 grams) into moles:
moles of H2C2O4.2H2O = (2.1000x10^-1 g) / (126.08 g/mol)
2. Next, use the balanced chemical equation to determine the mole ratio between oxalic acid dihydrate (H2C2O4.2H2O) and NaOH. The balanced equation is:
H2C2O4.2H2O + 2NaOH → 2NaC2O4 + 4H2O
The mole ratio between H2C2O4.2H2O and NaOH is 1:2. Therefore, the moles of NaOH used in the titration would be twice the moles of H2C2O4.2H2O.
moles of NaOH used = 2 * moles of H2C2O4.2H2O
3. Convert the volume of NaOH solution used (titration volume) from milliliters to liters:
volume of NaOH used = (2.63x10^1 mL) * (1 L / 1000 mL)
4. Finally, calculate the molarity of the NaOH solution using its definition:
Molarity (M) = moles of NaOH used / volume of NaOH used
5. Round the calculated molarity to three significant figures and express it in scientific notation if necessary.
By following these steps, you should be able to find the molarity of the NaOH solution using dimensional analysis.