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dexteright02
Hello!

We have the following data:

MM (Molar mass of Na2CO3) 
Na = 2*23 = 46 u
C = 1*12 = 12 u
O = 3*16 = 48 u
----------------------
MM (Molar mass of Na2CO3) = 46+12+48 = 106 g/mol
n (mol number) = 1 mol
m1 (mass of the solute) = ?

[tex]n = \dfrac{m_1}{MM} [/tex]

[tex]1\:mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}= \dfrac{m}{106\:g/mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}} [/tex]

[tex]m_1 = 1*106[/tex]

[tex]\boxed{m_1 = 106\:g}\Longleftarrow(solute\:mass)[/tex]

So if we have the dissolution in a liter (m2 - mass of solvent), that is 1000g , then the total mass of the solution (m) will be:

[tex]m\:(solution\:mass) = m_1\:(solute\:mass) + m_2\:(solvent\:mass) [/tex]

[tex]m = 106\:g+1000\:g [/tex]

[tex]\boxed{m = 1106\:g}\Longleftarrow(solution\:mass) [/tex]

Now, let's find the percentage in mass (% m / m), let's see:

[tex]\%(m/m) = \dfrac{m_1}{m}*100[/tex]

[tex]\%(m/m) = \dfrac{106}{1106}*100[/tex]

[tex]\%(m/m) = \dfrac{10600}{1106}[/tex]

[tex]\%(m/m) = 9.58408...\to\:\boxed{\boxed{\%(m/m) \approx 9.6}}\end{array}}\qquad\checkmark[/tex]

Answer: B) 9.6

I Hope this helps, greetings ... DexteR!

The percentage mass of sodium carbonate has been 9.6%. Thus, option B is correct.

The molality can be defined as the moles of solute in 1000 grams of solvent.

The given molality is 1m.

So, 1 mole of Sodium carbonate has been present in 1000 grams of solvent.

The molecular mass of sodium carbonate is 106 grams.

1 mole sodium carbonate = 106 grams.

So, 106 grams of solute has been present in 1000 grams of solvent.

The percent mass can be given by:

Percent mass = [tex]\rm \dfrac{Mass\;of\;solute}{Mass\;of\;solution}\;\times\;100[/tex]

Mass of solution = mass of solute + mass of solvent

Mass of solution = 106 grams + 1000 grams

Mass of solution = 1106 grams.

Percent mass of Sodium carbonate = [tex]\rm \dfrac{106}{1106}\;\times\;100[/tex]

Percent mass of sodium carbonate = 9.584 %

Percent mass of sodium carbonate = 9.6%

The percentage mass of sodium carbonate has been 9.6%. Thus, option B is correct.

For more information about percent mass, refer to the link:

https://brainly.com/question/19735910

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