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3 years ago

PLEASE HELP ME WITH THIS QUESTION THIS FREAKING SUCKS

Chemistry

1 answer:

tigry1 [53]3 years ago

8 0

Answer:

m = 0.122 m

Explanation:

Molality(m): A measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent.

$\mathrm{Molality\:Formula}:\quad \mathrm m = \dfrac{ mole\:of\:solute }{ mass\:of\:solvent\:in\:kg }$

$\mathrm m = \dfrac{ mole}{ kg }$

$\mathrm{Substitute\:the\:numbers\:into\:the\:"Molality\:Formula"}$

$\mathrm m = \dfrac{ 0.250 }{ 2.05 }$

$\mathrm{Divide\:0.250\:by\:2.05\:and\:get\:0.12195122}$

$\mathrm m = {0.12195122}$

$\mathrm{Round\:to\:the\:nearest\:thousandths\:place}$

$\mathrm m = 0.122$

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7 f Find the volume in dm3 and in mole of 0.505m of NaoH required to react with 40ml of 0.505m

Anna [14]

The volume of NaOH required is 0.08 dm³

To solve this question, we'll begin by writing the balanced equation for the reaction between H₂SO₄ and NaOH. This is illustrated below:

H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O

From the balanced equation above,

Mole ratio of the acid, H₂SO₄ $(n_{A}) = 1$

Mole ratio of the base, NaOH $(n_{B}) = 2$

Next, we shall determine the volume of NaOH required to react with H₂SO₄. This can be obtained as follow:

Molarity of the base, NaOH $(M_{B}) = 0.505 M$

Volume of the acid, H₂SO₄ $(V_{A}) = 40 mL$

Molarity of the acid, H₂SO₄ $(M_{A}) = 0.505 M$

<h3>Volume of the base, NaOH $(V_{B})$ =? </h3>

$\frac{M_{A} * V_{A}}{M_{B} * V_{B}} = \frac{n_{A}}{n_{B}}\\\\\frac{0.505 * 40}{0.505 *V_{B}} = \frac{1}{2}\\\\\frac{20.2}{0.505 *V_{B}} = \frac{1}{2}$

Cross multiply

$0.505 * V_{B} = 20.2 * 2\\0.505 * V_{B} = 40.4$

Divide both side by 0.505

$V_{B} = \frac{40.4}{0.505}\\\\V_{B} = 80 mL$

Finally, we shall convert 80 mL to dm³. This can be obtained as follow:

$1000 mL = 1 dm^{3}\\\\Therefore,\\\\80 mL = \frac{80 mL * 1dm^{3}}{1000 mL}\\\\80 mL = 0.08dm^{3}$

Therefore, the volume of NaOH required is 0.08 dm³

Learn more: brainly.com/question/19053582

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3 years ago

1. Is O2 a compound? Explain.

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4. It will be equal to 10 because of law of conservation of matter.

5. One observation can be that the compound, reaction you’re observing, has change states.

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3 years ago

The acid dissociation constant Ka of boric acid (H3BO3) is 5.8 times 10^-10. Calculate the pH of a 4.4 M solution of boric acid.

madam [21]

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