calculate the mass of sodium hydroxide needed to prepare 100 ml of a .10 m solution
To calculate the mass of sodium hydroxide needed to prepare a .10 M (molar) solution, you need to follow the formula:
molarity (M) = moles (mol) / volume (L)
First, convert the volume from milliliters (ml) to liters (L):
100 ml = 100/1000 = 0.1 L
Now, substitute the given values into the formula:
0.10 M = moles / 0.1 L
To find the number of moles, rearrange the formula:
moles = molarity × volume
moles = 0.10 mol/L × 0.1 L = 0.01 mol
Now, you need to determine the molar mass of sodium hydroxide (NaOH). The molar mass of an element can be found by summing up the atomic masses of its individual elements from the periodic table.
Sodium (Na) has an atomic mass of 22.99 g/mol.
Oxygen (O) has an atomic mass of 16.00 g/mol.
Hydrogen (H) has an atomic mass of 1.01 g/mol.
Add these masses together:
22.99 g/mol (Na) + 16.00 g/mol (O) + 1.01 g/mol (H) = 40.00 g/mol
Now, multiply the molar mass of NaOH by the number of moles:
0.01 mol × 40.00 g/mol = 0.40 grams
Therefore, you would need 0.40 grams of sodium hydroxide to prepare 100 ml of a 0.10 M solution.