How many grams of NaOH are contained in 500mL of 0.5M NaOH?

Answer 1

First, you must find the amount of moles of NaOH, using the concentration and volume given. By lowercase m, I'm assuming you mean molality, or molals of solution, which is the equation:

molality (m) = (moles of solute) / (total volume of solution (in liters))

To solve for moles of NaOH, your solute, rearrange the equation by multiplying volume on both sides to get:

moles solute = (molality)(total volume of solution)

Next, just plug in the information you know, which is 500 mL for the total volume and 125 m for the molality.

***Volume for concentration problems must be converted to liters, so remember that 1 L = 1000 mL

moles NaOH = (125 m)(0.500 L) = 62.5 moles

Finally, convert this to grams by finding the molar mass of NaOH using the Periodic Table:

22.99 + 16.00 + 1.008 = 39.998 g/mol

62.5 moles (39.998 g) / (1 mol) =249.875 grams NaOH

Answer 2

Molarity = moles of solute/Liters of solution (250 ml = 0.250 L)

get moles NaOH

0.5 M NaOH = X Moles NaOH/0.250 Liters

= 0.125 moles NaOH

===================now, find grams NaOH

0.125 moles NaOH (39.998 grams/1 mole NaOH)

= 5 grams NaOH needed

==================

Answer 3

First.

Molarity = moles of solute/Liters of solution ( 500 mL = 0.5 L )

0.5 M NaOH = X moles/0.5 L

= 0.25 moles NaOH

----------------------------

Second.

0.25 moles NaOH (39.998 grams/1 mole NaOH)

= 10 grams NaOH

=============

Answer 4

To prepare this solution, 0.080 mol of NaOH is needed, hence it is 0.080 x 40 = 3.200 grams.

Answer 5

2.5g