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torisob [31]
3 years ago
8

How many grams of sodium hydroxide are needed to make 250. Ml of a 7.80 m solution?

Chemistry
2 answers:
sashaice [31]3 years ago
7 0
<h3><u>Answer;</u></h3>

= 78 g of NaOH

<h3><u>Explanation;</u></h3>

Concentration = Moles of solute/Volume of solution

Thus;

Moles of the solute = Volume × Concentration

                                = 7.80 Moles/L × 0.250 L

                                 = 1.95 moles

But; 1 mole of NaOH = 40.0 g

Thus;

Mass of NaOH = moles × molar mass

                         = 1.95 moles × 40 g/mole

                        <u> = 78 g of NaOH</u>

Mkey [24]3 years ago
3 0

78 g of NaOH

<h3>Further explanation</h3>

Given:

  • The concentration of the NaOH solution that we want to make is 7.8 M.
  • The volume of NaOH solution that we want to make is 250 ml.

Question:

How many grams of sodium hydroxide are needed to make 250 ml of a 7.80 M solution?

The Process:

Step-1

Let us prepare the relative molecular mass (Mr) of NaOH.

  • Relative atomic mass: Na = 23, O = 16, and H = 1
  • Relative molecular mass (Mr) of NaOH = 23 + 16 + 1 = 40.

Step-2

The concentration of the solution is a mole of solute divided by 1 liter of solution.

\boxed{ \ M = \frac{n}{V} \ }  (Remember V in liters here)

We know that mole is mass divided by molecular mass.

\boxed{ \ n = \frac{mass}{Mr} \ }

The relationship between concentration (M), mass, relative molecular mass (Mr), and volume of solution in ml (V) is as follows:

\boxed{ \ M = \frac{mass}{Mr} \times \frac{1,000}{V} \ } (Remember V in ml here)

Substitute all known data into the equation.

\boxed{ \ 7.80 = \frac{mass}{40} \times \frac{1,000}{250} \ }

\boxed{ \ 7.80 = \frac{mass}{40} \times 4 \ }

\boxed{ \ 7.80 = \frac{mass}{10} \ }

Mass = 7.80 x 10

Mass = 78

Thus, the number of grams of sodium hydroxide are needed to make 250 ml of a 7.80 M solution is 78 grams.

_ _ _ _ _ _ _ _ _ _

Notes:

The concentration of the solution, especially in this case molarity, represents one significant data. Among them play a role in

  • determining the pH value (acid, base, or salt),
  • determining the value of the equilibrium constant, and
  • calculating osmotic pressure.
<h3>Learn more</h3>
  1. What is the concentration of a solution formed by diluting 25.0 ml of a 3.2 M NaCl solution to 135.0 ml?  brainly.com/question/12452615
  2. An example of the dilution of a solution brainly.com/question/4516437  
  3. How many moles of hno3 are present in the dilute solution? brainly.com/question/13501499

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