Question

What is the concentration if 20 grams of NaOH was dissolved in enough water to make a 250 mL NaOH solution?

Answer 1

The concentration of the NaOH solution, when 20 grams of NaOH are dissolved in enough water to make a 250 mL solution, is 2.0 M.

Step-by-step explanation:

Calculation of NaOH Solution Concentration

To calculate the concentration of a NaOH solution, you will first need to convert the mass of NaOH to moles using the molar mass. The molar mass of NaOH is 40.0 g/mol. Therefore, for 20 grams of NaOH, the number of moles (n) can be calculated as follows:

n = mass of NaOH / molar mass of NaOH = 20 g / 40.0 g/mol = 0.5 moles NaOH

Since the solution volume is 250 mL, we must convert this to liters to use it in the molarity calculation. 1 L = 1000 mL, so 250 mL is 0.250 liters.

The molarity (M) is the number of moles of solute (in this case, NaOH) per liter of solution, which can be calculated as:

Molarity (M) = moles of solute / liters of solution = 0.5 moles / 0.250 L = 2.0 M

Therefore, the concentration of the NaOH solution is 2.0 M.

Answer 2

Answer: 1 molar NaOH contains 40 grams of NaOH per every liter of water

Step-by-step explanation:

so 2 M NaOH contains twice that amount, ie. 80 grams per liter. Then, ine 250 ml of weater, there should be 80/4 = 20 grams of solid NaOH dissolved.