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2 years ago

Find the mass in grams of 0.75 moles of magnesium (Mg).

Chemistry

2 answers:

hoa [83]2 years ago

8 0

Answer:

$\boxed {\boxed {\sf 18.22875 \ g \ Mg}}$

Explanation:

We are asked to find the mass of 0.75 moles of magnesium.

Moles are converted to grams using the molar mass. This is the number of grams in 1 mole of a substance. The values are found on the Periodic Table because they are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.

Look up the molar mass of magnesium.

Mg: 24.305 g/mol

We convert using dimensional analysis. Set up a conversion factor using the molar mass.

$\frac { 24.305 \ g \ Mg}{1 \ mol \ Mg}$

We are converting 0.75 moles of magnesium to grams, so we multiply the conversion factor by this value.

$0.75 \ mol \ Mg *\frac { 24.305 \ g \ Mg}{1 \ mol \ Mg}$

The units of moles of magnesium cancel.

$0.75 *\frac { 24.305 \ g \ Mg}{1 }$

$0.75 *{ 24.305 \ g \ Mg}$

$18.22875 \ g \ Mg$

0.75 moles of magnesium contains 18.22875 grams of magnesium.

Lady bird [3.3K]2 years ago

3 0

Answer:

18.22874999999973

I recommend you to round the nearest 1 d.p

Explanation:

have a great day!

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3 years ago

At room temperature (20°C} and pressure, the density of air is 1.189 g/L. An object will float in air if its density is less tha

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Explanation:

$Density =\frac{Mass}[Volume}$

Density of the air ,d= 1.189 g/L

(a) Density of the evacuated ball

Mass of the ball ,m = 0.12 g

Volume of the ball = $V=560 cm^3=560 ml=0.560 L$

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(b) Density of the evacuated ball D = 0.214 g/L

Density of carbon dioxide gas = $d_1=1.830 g/L$

Mass of the carbon dioxide gas :

$1.830 g/L\times 0.560 L=1.0248 g$

Total density of filled ball with carbon dioxide gas:

$\frac{0.12 g+1.0248 g}{0.560 L}==2.044 g/L$

The ball filled with carbon dioxide will not float in the air because total density of filled ball is greater than the density of an air.

(c) Density of the evacuated ball D = 0.214 g/L

Density of hydrogen gas = $d_2=0.0899 g/L$

Mass of the hydrogen gas :

$1.830 g/L\times 0.560 L=0.050344 g$

Total density of filled ball with hydrogen gas:

$\frac{0.12 g+0.050344 g}{0.560 L}==0.3041 g/L$

The ball filled with hydrogen will float in the air because total density of filled ball is lessor than the density of an air.

(d) Density of the evacuated ball D = 0.214 g/L

Density of oxygen gas = $d_3=1.330 g/L$

Mass of the oxygen gas :

$1.330 g/L\times 0.560 L=1.7448 g$

Total density of filled ball with oxygen gas:

$\frac{0.12 g+1.7448 g}{0.560 L}=1.5442 g/L$

The ball filled with oxygen will not float in the air because total density of filled ball is greater than the density of an air.

(e) Density of the evacuated ball D = 0.214 g/L

Density of nitrogen gas = $d_4=1.165 g/L$

Mass of the nitrogen gas :

$1.165 g/L\times 0.560 L=0.6524 g$

Total density of filled ball with nitrogen gas:

$\frac{0.12 g+0.6524 g}{0.560 L}==1.3792 g/L$

The ball filled with nitrogen will not float in the air because total density of filled ball is greater than the density of an air.

f) Mass must be added to sink the ball = m

Density of ball > Density of the air ; to sink the ball.

$\frac{0.12g +m}{0.560L}>1.189 g/L$

m > 0.54584 g

For any case weight added to ball to make it sink in an air should be grater than the value of 0.54584 grams.

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Answer:

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Let us consider the fact that NH3 is a polar molecule and it is a general principle that like dissolves like. Hence, only H2S which is also a polar molecule can effectively interact with NH3 due to dipole-dipole interaction between the two molecules.

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Answer:

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Explanation:

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