how many grams of NaOH must be added to 0.250 litres of water to form a solution of PH=10.0?
NaOH is a strong base. As such it is 100% ionized; therefore, if pH = 10 then pOH = 4, and use pOH = -log(OH^-) to calculate (OH^-) in moles/L = molarity.
Then M = moles/L.
You know M and L, calculate moles.
Finally, moles = grams/molar mass.
Solve for grams.
1.00E-3 grams
To determine the number of grams of NaOH needed to form a solution with a pH of 10.0, we need information about the concentration of NaOH in the solution. The pH alone does not provide enough information to calculate the required amount.
If you have the concentration of NaOH in the solution, you can use the following steps to calculate the grams of NaOH needed:
1. Determine the molar mass of NaOH: The atomic mass of Na (sodium) is approximately 22.99 grams/mol, the atomic mass of O (oxygen) is approximately 16.00 grams/mol, and the atomic mass of H (hydrogen) is approximately 1.01 grams/mol. Adding these values, we get the molar mass of NaOH as 22.99 + 16.00 + 1.01 = 40.00 grams/mol.
2. Calculate the moles of NaOH needed: Convert the volume of water from liters to milliliters (ml). In this case, 0.250 liters is equal to 250 ml. Use the molarity equation: Molarity (mol/L) = Moles (mol) / Volume (L). Rearrange the equation to find the moles: Moles = Molarity × Volume. If you have the molarity, you can substitute the appropriate value. For example, if the molarity is 0.1 mol/L, then the moles of NaOH needed would be Moles = 0.1 mol/L × 0.250 L = 0.025 mol.
3. Convert moles to grams: Multiply the moles of NaOH needed by the molar mass of NaOH to convert to grams. Using the moles from the previous step, multiply by the molar mass: Grams = Moles × Molar mass. For example, if the moles calculated are 0.025 mol, then the grams of NaOH needed would be Grams = 0.025 mol × 40.00 g/mol = 1.00 g.
Therefore, if you know the concentration of NaOH in the solution, you can use the steps above to calculate the grams of NaOH needed to form a solution with a pH of 10.0.