How many grams of NaOH are required to prepare 250 mL of 0.205 M NaOH? SHOW ALL WORK and include units.
I don't know how to set this up.
How many mols do you need? That's M x L = mols.
Then grams = mols/molar mass. You know molar mass and mols, solve for grams.
To find the number of grams of NaOH required to prepare a certain concentration of a solution, you need to follow these steps:
1. Determine the molecular weight of NaOH.
2. Calculate the number of moles of NaOH using the formula: moles = concentration (M) × volume (L).
3. Convert the moles of NaOH to grams using the formula: grams = moles × molecular weight.
Now, let's calculate the number of grams of NaOH required to prepare the given solution:
Step 1: Determine the molecular weight of NaOH.
The molecular weight of NaOH is the sum of the atomic weights of each atom in the compound. The atomic weight of sodium (Na) is 22.99 g/mol, oxygen (O) is 16.00 g/mol, and hydrogen (H) is 1.01 g/mol.
Molecular weight of NaOH = atomic weight of Na + atomic weight of O + atomic weight of H
= 22.99 g/mol + 16.00 g/mol + 1.01 g/mol
= 39.99 g/mol
Step 2: Calculate the number of moles of NaOH.
We have the concentration of NaOH as 0.205 M and the volume as 250 mL. However, we need to convert the volume to liters to match the unit of concentration.
Volume in liters = 250 mL ÷ 1000 mL/L
= 0.250 L
Moles of NaOH = concentration (M) × volume (L)
= 0.205 M × 0.250 L
= 0.05125 mol
Step 3: Convert the moles of NaOH to grams.
To convert moles to grams, we need to multiply the number of moles by the molecular weight of NaOH.
Grams of NaOH = moles × molecular weight
= 0.05125 mol × 39.99 g/mol
≈ 2.05 g
Therefore, approximately 2.05 grams of NaOH are required to prepare 250 mL of a 0.205 M NaOH solution.