Find percent composition, 20 grams of NaOH is dissolved in enough water to make 1 liter of solution
To find the percent composition of a substance in a solution, we need to calculate the mass of the substance in the solution and then divide it by the total mass of the solution and multiply by 100.
First, let's calculate the molar mass of NaOH:
Na = 22.99 g/mol
O = 16.00 g/mol
H = 1.01 g/mol
Molar mass of NaOH = 22.99 + 16.00 + 1.01 = 40.00 g/mol
Next, we need to calculate the number of moles of NaOH in 20 grams:
Number of moles = mass / molar mass
Number of moles = 20 g / 40.00 g/mol = 0.5 moles
Since 1 mole of NaOH is dissolved in enough water to make 1 liter of solution, you have 0.5 moles of NaOH in 1 liter of solution.
Now, let's find the total mass of the solution using the density of water (1 g/mL):
Total mass of 1 liter of solution = 1 L x 1000 mL/L x 1 g/mL = 1000 grams
Now, we can calculate the percent composition of NaOH in the solution:
Percent composition = (mass of NaOH / total mass of solution) x 100
Percent composition = (20 g / 1000 g) x 100
Percent composition = 2%
Therefore, the percent composition of NaOH in the solution is 2%.