1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Iteru [2.4K]
3 years ago
13

What is the mass of 4.99×1021 platinum atoms?

Chemistry
1 answer:
charle [14.2K]3 years ago
8 0

Answer:

\boxed {\boxed {\sf 1.62 \ g \ Pt}}

Explanation:

We are asked to find the mass of a number of platinum (Pt) atoms.

<h3>1. Convert Atoms to Moles </h3>

First, we convert atoms to moles using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are platinum atoms.

We will convert using dimensional analysis so we set up a ratio using the information we know (6.022 × 10²³ platinum atoms in 1 mole of platinum).

\frac {6.022 \times 10^{23} \ atoms \ Pt}{ 1 \ mol \ Pt}

We are converting 4.99 ×10²¹ atoms of Pt to moles of Pt, so we multiply by this value.

4.99 \times 10^{21} \ atoms \ Pt *\frac {6.022 \times 10^{23} \ atoms \ Pt}{ 1 \ mol \ Pt}

Flip the ratio so the units of atoms of platinum cancel.

4.99 \times 10^{21} \ atoms \ Pt *\frac { 1 \ mol \ Pt}{6.022 \times 10^{23} \ atoms \ Pt}

4.99 \times 10^{21} *\frac { 1 \ mol \ Pt}{6.022 \times 10^{23}}

\frac { 4.99 \times 10^{21}}{6.022 \times 10^{23}} \ mol \ Pt

Divide.

0.008286283627 \ mol \ Pt

<h3>2. Convert Moles to Grams </h3>

Next, we convert moles to grams using the molar mass. This is the mass of 1 mole of a substance. This is found on the Periodic Table because it is equivalent to the atomic mass, but the units are grams per mole instead of atomic mass units. Look up platinum's molar mass.

  • Pt: 195.08 g/mol

Set up another ratio using this new information (195.08 grams of Pt in 1 mole of Pt).

\frac {195.08 \ g \ Pt}{ 1 \ mol \ Pt}

Multiply by the number of moles we just calculated.

0.008286283627 \ mol \ Pt*\frac {195.08 \ g \ Pt}{ 1 \ mol \ Pt}

The units of moles of platinum cancel.

0.008286283627*\frac {195.08 \ g \ Pt}{ 1 }

0.008286283627* {195.08 \ g \ Pt}

1.61648821\ g \ Pt

<h3>3. Round</h3>

The original measurement of atoms ( 4.99 ×10²¹ ) has 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 6 in the thousandth place tells us to round the 1 up to a 2.

1.62 \ g \ Pt

There are approximately <u>1.62 grams of platinum</u> in 4.99 ×10²¹ atoms of platinum.

You might be interested in
Which of these is an example of a physical property?
Margarita [4]
The woods so far the texture is going to be A with the Henry
3 0
2 years ago
Help help help help help help help help
ohaa [14]

Answer:Switch off lighting in refrigeration areas when not in use?

Explanation:

7 0
2 years ago
The minimum energy required to break the oxygen-oxygen bond in oxygen is 495 kJ/mol. What is the longest wavelength of radiation
Sergeeva-Olga [200]

Answer:

241 nm, it is UV light range

Explanation:

The minimum energy needed required to break the oxygen-oxygen bond = 495 kJ/mol

Energy needed for 1 molecule of oxygen = 495 × 10³ J / avogadro's constant = 495 × 10³ J  / ( 6.02 × 10²³) = 8.223 × 10⁻¹⁹ J

Energy = hv

where h = Planck constant = 6.626 × 10 ⁻³⁴ m²kg/s and v = frequency

c speed of light = vλ

c / λ = v

E = hc / λ

λ  = hc / E = (6.626 × 10 ⁻³⁴ m²kg/s × 3.0 × 10 ⁸ m/s) / (8.223 × 10⁻¹⁹ J)  = 2.41 × 10⁻⁷m = 241 nm

UV light wavelength is between 400 nm - 10 nm

4 0
3 years ago
Please and thank you!
Valentin [98]

Answer:

7.5 moles of O₂.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2KClO₃ —> 2KCl + 3O₂

From the balanced equation above,

2 moles of KClO₃ decomposed to produce 3 moles of O₂.

Finally, we shall determine the number of mole of O₂ produced by the decomposition of 5 moles of KClO₃. This can be obtained as follow:

From the balanced equation above,

2 moles of KClO₃ decomposed to produce 3 moles of O₂.

Therefore, 5 moles of KClO₃ will decompose to produce = (5 × 3)/ 2 = 7.5 moles of O₂.

Thus, 7.5 moles of O₂ were obtained from the reaction.

3 0
2 years ago
The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can.
julia-pushkina [17]
I think the answer is ( A and C ) why I picked a and c it’s because a and c look the same answer. I hope it helped you
8 0
3 years ago
Other questions:
  • Can you plz answer this question: The ocean supply about 90 percent of the ————— water that goes inti the water cycle
    9·1 answer
  • What is the source of energy that is released in an exothermic reaction? what absorbs the energy that is released ?
    11·1 answer
  • Which of the following reactions will proceed as drawn below? (Yes or No)
    6·1 answer
  • A flashbulb of volume 2.70 mL contains O2(g) at a pressure of 2.30 atm and a temperature of 30.0 °C. How many grams of O2(g) doe
    14·1 answer
  • What ions and/or molecules (apart from water) are present in relatively large proportions in a solution of a weak acid hclo (aq)
    7·1 answer
  • 6. We have many vestigial structures that are similar to structures on modern day chimpanzees. How can we
    15·1 answer
  • How can a Hydrogen atom turn into a<br> Hydrogen ion (H+)?
    12·1 answer
  • Describe the whole process of Aluminum extraction from bauxite.​
    12·2 answers
  • ANSWERIT AND YOU WILL BE MARKED THE BRAINLIEST
    11·2 answers
  • Which part of the hunman body controls the nervous system
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!