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3 years ago

A.) What is the mass in g of 5 mols of Mg?

Chemistry

1 answer:

Dovator [93]3 years ago

6 0

Answer:

Mass of Mg = 120 g

1.23 moles of Cu

Explanation:

Given data:

Number of moles of Mg = 5 mol

Mass of Mg = ?

Solution:

Number of moles = mass/molar mass

Molar mass of magnesium is 24 g/mol.

5 mol = mass/ 24 g/mol

Mass = 5 mol × 24 g/mol

Mass = 120 g

B) Given data:

Number of atoms of Cu = 7.4 ×10²³ atom

Number of moles of Cu = ?

Solution:

Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

7.4 ×10²³ atom × 1 mol / 6.022 × 10²³ atom

1.23 moles of Cu

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A student reacts 5.0 g of sodium with 10.0 g of chlorine and collect 5.24 g of sodium chloride. What is the percent yield of thi

Ede4ka [16]

Answer: The percent yield of this combination reaction is 41.3 %

Explanation : Given,

Mass of $Na$ = 5.0 g

Mass of $Cl_2$ = 10.0 g

Molar mass of $Na$ = 23 g/mol

Molar mass of $Cl_2$ = 71 g/mol

First we have to calculate the moles of $Na$ and $Cl_2$ .

$\text{Moles of }Na=\frac{\text{Given mass }Na}{\text{Molar mass }Na}$

$\text{Moles of }Na=\frac{5.0g}{23g/mol}=0.217mol$

and,

$\text{Moles of }Cl_2=\frac{\text{Given mass }Cl_2}{\text{Molar mass }Cl_2}$

$\text{Moles of }Cl_2=\frac{10.0g}{71g/mol}=0.141mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation will be:

$2Na+Cl_2\rightarrow 2NaCl$

From the balanced reaction we conclude that

As, 2 mole of $Na$ react with 1 mole of $Cl_2$

So, 0.217 moles of $Na$ react with $\frac{0.217}{2}=0.108$ moles of $Cl_2$

From this we conclude that, $Cl_2$ is an excess reagent because the given moles are greater than the required moles and $Na$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $NaCl$

From the reaction, we conclude that

As, 2 mole of $Na$ react to give 2 mole of $NaCl$

So, 0.217 mole of $HCl$ react to give 0.217 mole of $NaCl$

Now we have to calculate the mass of $NaCl$

$\text{ Mass of }NaCl=\text{ Moles of }NaCl\times \text{ Molar mass of }NaCl$

Molar mass of $NaCl$ = 58.5 g/mole

$\text{ Mass of }NaCl=(0.217moles)\times (58.5g/mole)=12.7g$

Now we have to calculate the percent yield of this reaction.

Percent yield = $\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100$

Actual yield = 5.24 g

Theoretical yield = 12.7 g

Percent yield = $\frac{5.24g}{12.7g}\times 100$

Percent yield = 41.3 %

Therefore, the percent yield of this combination reaction is 41.3 %

4 0

3 years ago

The periodic table is based on an element's

grin007 [14]

Well, TECHNICALLY, the periodic table is "based" upon a whole myriad of characteristics. But if you're talking about the consecutive arrangement of elements...it would be B, the atomic number.

3 0

3 years ago

Can someone answer dis:

SVEN [57.7K]

Answer:

If we subtract the atomic number from the atomic mass: atomic mass - atomic number = number of protons + number of neutrons - number of protons. Thus we get the number of neutrons present in an atom when we subtract the atomic number from the atomic mass.

Explanation: hope this helps???

7 0

3 years ago

Read 2 more answers

A solution of malonic acid, H2C3H2O4 , was standardized by titration with 0.1000 M NaOH solution. If 21.17 mL of the NaOH soluti

MrRa [10]

Answer: The molarity of the malonic acid solution is 0.08335 M

Explanation:

$H_2C_3H_2O_4 +2NaOH\rightarrow Na_2C_3H_2O_4+2H_2O$