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 0.10 M solution, you will need to use the equation:

Molarity (M) = moles of solute / volume of solution (in liters)

First, convert the volume of solution from milliliters to liters:
100 ml = 100/1000 = 0.1 L

Now, rearrange the equation to solve for moles of solute:
moles of solute = Molarity × volume of solution

Substitute the given values:
moles of solute = 0.10 M × 0.1 L

Now we can calculate the moles of sodium hydroxide required.

Next, find the molar mass of sodium hydroxide (NaOH).

Na (sodium) has a molar mass of 22.99 g/mol,
O (oxygen) has a molar mass of 16.00 g/mol,
H (hydrogen) has a molar mass of 1.01 g/mol.

Adding them together:
22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 40.00 g/mol

Therefore, the molar mass of NaOH is 40.00 g/mol.

Finally, multiply the moles of solute by the molar mass of sodium hydroxide:
mass = moles of solute × molar mass of NaOH

Substitute the calculated values:
mass = (0.10 M × 0.1 L) × 40.00 g/mol

Calculating the mass of sodium hydroxide needed will give you the final answer.