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3 years ago

Find the molar mass of oxygen gas

Chemistry

1 answer:

Mazyrski [523]3 years ago

6 0

Molar mass of oxygen = mass of an oxygen atom×2 = 15.999×2 ≈16×2 = 32

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Calculate the number of grams in 4.56 x 1026 atoms of sodium phosphate. Be sure to balance the charges of sodium phosphate. Help

zalisa [80]

Answer:

124225.91 g of Na₃PO₄

Explanation:

From the question given above, the following data were obtained:

Number of atoms of Na₃PO₄ = 4.56×10²⁶ atoms

Mass of Na₃PO₄ =?

From Avogadro's hypothesis,

6.02×10²³ atoms = 1 mole of Na₃PO₄

Next, we shall determine the mass of 1 mole of Na₃PO₄. This can be obtained as follow:

1 mole of Na₃PO₄ = (23×3) + 31 + (16×4)

= 69 + 31 + 64

= 164 g

Thus,

6.02×10²³ atoms = 164 g of Na₃PO₄

Finally, we shall determine the mass of Na₃PO₄ that contains 4.56×10²⁶ atoms. This can be obtained as follow:

6.02×10²³ atoms = 164 g of Na₃PO₄

Therefore,

4.56×10²⁶ atoms = (4.56×10²⁶ × 164)/6.02×10²³

4.56×10²⁶ atoms = 124225.91 g of Na₃PO₄

Therefore, 124225.91 g of Na₃PO₄ contains 4.56×10²⁶ atoms

4 0

2 years ago

It takes 495.0 kJ of energy to remove 1 mole of electron from an atom on the surface of sodium metal. How much energy does it ta

Zigmanuir [339]

Answer:

$\lambda=241.9\ nm$

Explanation:

The work function of the sodium= 495.0 kJ/mol

It means that

1 mole of electrons can be removed by applying of 495.0 kJ of energy.

Also,

1 mole = $6.023\times 10^{23}\ electrons$

So,

$6.023\times 10^{23}$ electrons can be removed by applying of 495.0 kJ of energy.

1 electron can be removed by applying of $\frac {495.0}{6.023\times 10^{23}}\ kJ$ of energy.

Energy required = $82.18\times 10^{-23}\ kJ$

Also,

1 kJ = 1000 J

So,

Energy required = $82.18\times 10^{-20}\ J$

Also, $E=\frac {h\times c}{\lambda}$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

So,

$79.78\times 10^{-20}=\frac {6.626\times 10^{-34}\times 3\times 10^8}{\lambda}$

$\lambda=\frac{6.626\times 10^{-34}\times 3\times 10^8}{82.18\times 10^{-20}}$

$\lambda=\frac{10^{-26}\times \:19.878}{10^{-20}\times \:82.18}$

$\lambda=\frac{19.878}{10^6\times \:82.18}$

$\lambda=2.4188\times 10^{-7}\ m$

Also,

1 m = 10⁻⁹ nm

So,

$\lambda=241.9\ nm$

6 0

2 years ago

.1 Write 'a' 'an' or 'the' where is necessary.

kolezko [41]

The answers

A) a
B) a
C) an
D) the

5 0

2 years ago

What is the balance equation for copper metal and aqueous zinc nitrate

AnnZ [28]

Answer:

No reaction

Explanation:

Single-displacement reaction is the chemical reaction in which one metal which has higher negative redox potential replaces the another from it's salt solution.

Thus, Cu cannot replaces zine from its salt as it is less reactive than zince.

However, zinc can replace copper from its salt as:

$Zn_{(s)}+Cu(NO_3)_2_{(aq)}\rightarrow Cu_{(s)}+Zn(NO_3)_2_{(aq)}$

3 0

2 years ago

Calculate the Cal(kcal) in 1 cup of whole milk: 12 g of carbohydrate, 9 g of fat, and 9 g of protein.

laiz [17]

Fat: 1 gram = 9 calories Protein: 1 gram = 4 calories Carbohydrates: 1 gram = 4 calories Alcohol: 1 gram = 7 calories"
So, (12 g carbohydrates)*4 Cal=48 Cal; (9 g fat) *9 Cal=81 Cal; (9 g protein)*4 Cal=36 Cal
48 Cal + 81 Cal + 36 Cal = 165 Cal in one glass of milk

5 0

3 years ago

Read 2 more answers