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vesna_86 [32]
3 years ago
12

A cube made of platinum (Pt) has an edge length of 1.0 cm. (a) Calculate the number of Pt atoms in the cube. (b) Atoms are spher

ical in shape. Therefore, the Pt atoms in the cube cannot fill all the available space. If only 74 percent of the space inside the cube is taken up by Pt atoms, calculate the radius in picometers of a Pt atom. The density Pt is 21.45 g/cm3, and the mass of a single Pt atom is 3.240 x 10^-22 g. (The volume of a sphere of radius r is 4/5Ïr^3).
Chemistry
1 answer:
irina1246 [14]3 years ago
3 0

Answer:

a)The total number of platinum atoms are 6.620\times 10^{22} atoms.

b)The radius of a Pt atom is 138.7 pm.

Explanation:

a) Let the total number of platinum atoms be x

And mass of x atoms of platinum be m

Edge length of platinum cube ,s= 1.0 cm

Volume of the cube = 1.0 cm^3

Density of the platinum cube = d=21.45 g/cm^3

Mass = Density × Volume

(m)=21.45 g/cm^3\times 1.0 cm^3=21.45 g

Mass of an atom of platinum = 3.240\times 10^{-22} g

x\times 3.240\times 10^{-22} g=21.45 g

x=6.620\times 10^{22} atoms

b) If only 74 percent of the space inside the cube is taken up by Pt atoms.

Volume occupied by platinum atoms = 74% of 1.0 cm^3

V'= 0.74 cm^3

Volume occupied by 6.620\times 10^{22} atoms is0.74 cm^3.

6.620\times 10^{22} \times \frac{4}{3}\pi r^3=V'

6.620\times 10^{22} \times \frac{4}{3}\times 3.14\times r^3=0.74 cm^3

r = 1.387\times 10^{-8} m = 138.7 pm

The radius of a Pt atom is 138.7 pm.

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Ksenya-84 [330]

At constant temperature, if the pressure is compressed to the given value, the volume of the nitrogen gas increases to 23.2L.

<h3>What is Boyle's law?</h3>

Boyle's law simply states that "the volume of any given quantity of gas is inversely proportional to its pressure as long as temperature remains constant.

Boyle's law is expressed as;

P₁V₁ = P₂V₂

Where P₁ is Initial Pressure, V₁ is Initial volume, P₂ is Final Pressure and V₂ is Final volume.

Given that;

  • Initial volume of the gas V₁ = 22.5L
  • Initial pressure of the gas P₁ = 0.98atm
  • Final pressure of the gas P₂ = 0.95atm
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P₁V₁ = P₂V₂

V₂ = P₁V₁ / P₂

V₂ = (0.98atm × 22.5L) / 0.95atm

V₂ = 22.05Latm / 0.95atm

V₂ = 23.2L

Therefore, at constant temperature, if the pressure is compressed to the given value, the volume of the nitrogen gas increases to 23.2L.

Learn more about Boyle's law here: brainly.com/question/1437490

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6 0
2 years ago
4P+ 5O2 -&gt; P4O10
Ratling [72]
If 4 moles of P is used by 5 mole of O2
then....0.489 moles will be used by 5/4 × .489 = .611 moles of O2

so .611 moles

so if 4 moles of P is burnt , 1 mole of P4O10 is produced ....so for .489 moles...... .489/4=.122 moles !
so mass will be .122× 283.89 = 34.7 grams

so first ans is .611 moles and second is 34.7 grams !

if you have any problem regarding this , just comment !!!
4 0
3 years ago
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BlackZzzverrR [31]

Answer:

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Explanation:

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Answer:

When barium chloride (BaCl 2) is dissolved in water, the water conducts electricity. In what form will the dissolved BaCl 2 be found? a. as Ba 2+ and Cl - ions b. as Ba atoms and Cl 2 molecules

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