what is the total # of grams of NaOH(formula mass=40) needed to make 1.0 liter of a 0.20 M solution
a. 80.g
b. 2.0g
c. 8.0g
d. 20.g
Go back to the molarity definition.
is the answer b
molarity = #mols/L
0.20 M means we want # mols in 1 L to be 0.20 mols. grams = mols x molar mass = 0.2 x 40 = ??
C?
0.20 x 40 = 8.0g
Yes, you are correct. The answer is c. 8.0g.
To determine the total number of grams of NaOH needed to make a 0.20 M solution, you need to use the molarity definition. Molarity is defined as the number of moles of solute per liter of solution.
In this case, we want a 0.20 M solution of NaOH in 1.0 liter. We know that the molar mass of NaOH is 40 g/mol. So, we can use the formula:
grams = moles x molar mass
To find the number of moles, we can rearrange the molarity formula:
moles = molarity x volume (in liters)
Since we want 0.20 moles in 1.0 liter, the number of moles is 0.20 x 1 = 0.20 moles.
Now, we can substitute this value into the grams formula:
grams = 0.20 moles x 40 g/mol = 8.0g
Therefore, the total number of grams of NaOH needed to make a 0.20 M solution is 8.0g.