A sample of solid monoprotic acid with molar mass equal to 137.9 g/mol was titrated with 0.1879 M sodium hydroxide solution. Calculate the mass in grams of acid to be used if the volume of NaOH to be used is 25 mL.
L(NaOH) x M(NaOH) = mols(NaOH)
Mols NaOH = mols acid
g acid/molar mass acid = mols acid
solve for g acid.
Post your work if you get stuck.
0.1879M x 0.025L = 4.6975 mols
4.6975 x 137.9 = 647.78 changes 0.647gm
I am not sure answer who tells me the right. Pls help
To calculate the mass of acid to be used, we need to use the concept of molar mass and the given concentration and volume of the sodium hydroxide solution.
1. Start by calculating the number of moles of sodium hydroxide (NaOH) using the given concentration and volume:
Moles of NaOH = concentration (M) x volume (L)
Moles of NaOH = 0.1879 M x 0.025 L (convert mL to L)
Moles of NaOH = 0.00469875 mol
2. Based on the balanced chemical equation for the reaction between the acid and NaOH, we know that 1 mole of acid reacts with 1 mole of NaOH. Therefore, the number of moles of acid is also 0.00469875 mol.
3. Use the molar mass of the acid to calculate the mass of the acid:
Mass of acid (g) = moles of acid x molar mass (g/mol)
Mass of acid (g) = 0.00469875 mol x 137.9 g/mol
Mass of acid (g) ≈ 0.64636 g
Therefore, the mass of acid to be used is approximately 0.64636 grams.