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
Artist 52 [7]
3 years ago
12

A 67.2 g sample of a gold and palladium alloy contains 3.28×1023 atoms .

Chemistry
1 answer:
PSYCHO15rus [73]3 years ago
5 0
One mole of any substance contains 6.022 x 10^23 atoms
Therefore, number of moles containing <span>3.28×10^23 atoms can be calculated as follows:
number of moles = (3.28 x 10^23) / (6.022 x 10^23) = 0.544 moles

From the periodic table:
molecular mass of gold = 197 grams
molecular mass of palladium = 106.4 grams
Therefore:
molar mass of gold = 197 grams
molar mass of palladium = 106.7 grams

First equation:
moles of gold + moles of palladium = 0.544 moles

Second equation:
mass of gold + mass of palladium = 67.2 grams
mass can be written as: mass = number of moles x molar mass
therefore:
(mass of gold + mass of palladium) can be rewritten as:
moles of gold x 197 + moles of palladium x 106.4 = 67.2 grams

Now, we have two equations (highlighted in bold) in two unknowns, we can solve them simultaneously to get the number of moles of each element as follows:
From equation one:
moles of gold = 0.544 - moles of palladium
Substitute with this in equation 2:
</span>(0.544 - moles of palladium) x 197 + moles of palladium x 106.4 = 67.2
 107.168 - 197 moles of palladium + 106.4 moles of palladium = 67.2
107.168 - 67.2 = 197 moles of palladium - 106.4 moles of palladium
39.968 = 90.6 moles of palladium
moles of palladium = 0.4411 moles
Substitute in equation 1 to get moles of gold:
moles of gold = 0.544 - 0.4411 = 0.1029 moles

Now, the last step is to convert the number of moles to mass:
mass = number of moles x molar mass
mass of gold = 0.1029 x 197 = 20.2713 grams
mass of palladium = 0.4411 x 106.4 = 46.93304 grams
You might be interested in
Describe what it means for something to be an acid.
Oduvanchick [21]
A sour-tasting material (usually in a solution) that dissolves metals and other materials. Technically, a material that produces positive ions in solution. An acid<span> is the opposite of a base and has a pH of 0 to 7.</span>
5 0
3 years ago
Read 2 more answers
What happens in a voltaic cell?
nirvana33 [79]

Answer:

Hi ,

Answer:

A chemical energy is changed to a electrical energy

3 0
3 years ago
The electron configuration of an element is shown below.
g100num [7]

Answer:

helium family or neon family

Explanation:

you can use p

5 0
3 years ago
A chemist must dilute 34.3mL of 1.72mM aqueous calcium sulfate solution until the concentration falls to 1.00mM. He'll do this b
EastWind [94]

Answer:

58.9mL

Explanation:

Given parameters:

Initial volume  = 34.3mL    = 0.0343dm³

Initial concentration  = 1.72mM   = 1.72 x 10⁻³moldm⁻³

Final concentration  = 1.00mM = 1 x 10⁻³ moldm⁻³

Unknown:

Final volume  =?

Solution:

Often times, the concentration of a standard solution may have to be diluted to a lower one by adding distilled water. To find the find the final volume, we must recognize that the number of moles of the substance in initial and final solutions are the same.

   Therefore;

              C₁V₁  =  C₂V₂

where C and V are concentration and 1 and 2 are initial and final states.

        now input the variables;

                      1.72 x 10⁻³ x  0.0343 = 1 x 10⁻³  x V₂

                        V₂ = 0.0589dm³ = 58.9mL

         

4 0
3 years ago
Which of the following would have the best thermal insulation properties? A. A paper cup B. a plastic cup C. a thick mug D. a cu
Vadim26 [7]

<em>From the above options, the best </em><em>Thermal insulator </em><em>will be a </em><em>Plastic cup.</em>

Option (b);

<u>Explanation</u>

Thermal insulators resist to conduct energy or reduction of heat transfer when objects come across in contact with radiation or higher heat object. To conduct energy we need metal or those materials which contain free electrons in it to move from one metal to another.

Plastic doesn't have metallic character so it will resist the heat up to some threshold. Mostly this material is used in separating two current-conducting material. There are many other examples of thermal insulator such as Rubber, fabrics, paper, wood, wool.

6 0
3 years ago
Read 2 more answers
Other questions:
  • What happens if you don't use enough solvent for a recrystallization?
    9·1 answer
  • I’m confused on question 13
    14·1 answer
  • Please help
    14·2 answers
  • Identify each number that is given is scientific notation
    9·1 answer
  • Changing atmospheric conditions, like increasing carbon dioxide content, might possibly _____.
    7·1 answer
  • Contrast How are photosynthesis and cellular respiration different?
    6·1 answer
  • A block has a mass of 30g and dimensions of 1.5cm by 4.8cm by 2.3 cm. Will the block float or sink in
    6·1 answer
  • Which of the following samples will have the greatest volume at STP?
    12·1 answer
  • What is the pH of a solution whose hydronium concentration is 3.5 x 10^(-3) M?<br><br> Thanks!
    10·1 answer
  • 7.
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!