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3 years ago

The percent composition by mass of magnesium MgBr2 (gram formula mass= 184 grams/mole) is equal to...

2 answers:

4 0

The percent composition by mass of an element is determined by dividing the molar mass of the element by the molar mass of the compound. In this case, the molar mass of magnesium is 24. Hence the answer to this problem is A. 24/184 x 100

uranmaximum [27]3 years ago

3 0

Answer:

Explanation:

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Answer:

yes they're gay

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2 years ago

An unknown amount of acid can often be determined by adding an excess of base and then back-titrating the excess. A 0.3471−g sam

MAXImum [283]

Explanation:

The given data is as follows.

Mass of mixture = 0.3471 g

As the mixture contains oxalic acid and benzoic acid. So, oxalic acid will have two protons and benzoic acid has one proton.

This means oxalic acid will react with 2 moles of NaOH and benzoic acid will react with 1 mole of NaOH.

Hence, moles of NaOH in 97 ml = $\frac{0.1090 \times 97}{1000}$

= $10.573 \times 10^{-3} mol$

Moles of HCl in 21.00 ml = $\frac{0.2060 \times 21}{1000}$

= $4.326 \times 10^{-3}$ mol

Therefore, total moles of NaOH that reacted are as follows.

$10.573 \times 10^{-3} mol$ - $4.326 \times 10^{-3} mol$

= $6.247 \times 10^{-3}$ mol

So, total 3 mole of NaOH will react with 1 mole of mixture. Therefore, number of moles of NaOH reacted with benzoic acid is as follows.

$\frac{6.247 \times 10^{-3}}{3}$

= $2.082 \times 10^{-3}$ mol

Since, molar mass of NaOH is 40 g/mol. Therefore, calculate the mass of NaOH as follows.

$2.082 \times 10^{-3} mol \times 40 g/mol$

= $83.293 \times 10^{-3}$ g

= 0.0832 g

Whereas molar mass of benzoic acid is 122 g/mol.

Therefore, 40 g NaOH = 122 g benzoic acid

So, 0.0832 g NaOH = $\frac{122 g}{40 g} \times 0.0832 g$

= 0.253 g

Hence, calculate the % mass of benzoic acid as follows.

$\frac{0.253 g}{0.3471 g} \times 100$

= 73.10%

Thus, we can conclude that mass % of benzoic acid is 73.10%.

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3 years ago

What are two factors that affect an objects kinetic energy

Bad White [126]

Potential energy and height; best guess;)

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3 years ago

Read 2 more answers

Andre is packing for a move to Kentucky. He needs to pack 20 small paperback books whose total mass is 5 kg and some pillows who

storchak [24]

The pillows because it is larger than paperback books, in this situation just think about which is larger, I pretty sure Andre is not going to hold the boxes in his hand.
hope I helped

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3 years ago

Is this right, I feel like its wrong

hjlf

It is correct, next time re-check your answer and don't second guess yourself. ;3

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3 years ago