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
Sergio [31]
3 years ago
9

The half-life of I-37 is 8.07 days. If 25 grams are left after 40.35 days, how many grams were in the original sample?

Chemistry
1 answer:
andreev551 [17]3 years ago
3 0

Answer:

800 g

Explanation:

We can express the decay of I-37 using the formula:

  • Final Mass = Initial Mass * 0.5^{\frac{Time}{Half-Life} }

We <u>input the data</u>:

  • 25 g = Initial Mass * 0.5^{(\frac{40.35}{8.07})}

And <u>solve for Initial Mass</u>:

  • 25 g = Initial Mass * 0.5^{5}
  • 25 g = Initial Mass * 0.03125
  • Initial Mass = 800 g

Meaning that out 800 grams of I-37, only 25 will remain after 40.35 days.

You might be interested in
Plz help guys ASAP! <br> Thanks in advance
MariettaO [177]

Answer:

3.6 moles

Explanation:

The balanced equation for the reaction is given below:

N₂ + 3H₂ —> 2NH₃

From the balanced equation above,

1 mole of N₂ reacted with 3 moles of H₂ to produce 2 moles NH₃.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

1 mole of N₂ reacted with 3 moles of H₂.

Therefore, 3.2 moles of N₂ will react with = 3.2 × 3 = 9.6 moles of H₂.

From the calculation made above, we can see that it will take a higher amount (i.e 9.6 moles) of H₂ than what was given (i.e 5.4 moles) to react completely with 3.2 moles of N₂.

Therefore, H₂ is the limiting reactant and N₂ is the excess reactant.

Finally, we the greatest quantity of ammonia, NH₃ produced from the reaction.

In this case, the limiting reactant will be use because all of it is consumed in the reaction.

The limiting reactant is H₂ and greatest quantity of ammonia, NH₃ produced can be obtained as follow:

From the balanced equation above,

3 moles of H₂ reacted to produce 2 moles NH₃.

Therefore, 5.4 of H₂ will react to produce = (5.4 × 2)/3 = 3.6 moles of NH₃

Thus, the greatest quantity of ammonia, NH₃ produced from the reaction is 3.6 moles

4 0
3 years ago
Assume the average apple has a mass of 167 grams. How many apples are in a bag of apples that weighs 2000 grams? Enter your numb
forsale [732]

Answer:

12

Explanation:

167x=2000

x=11.976

rounds to 12

4 0
3 years ago
Calculate the mean of 2, 5 and 3. write your answer to 2 decimal places. please help me on this
makvit [3.9K]

Hello.

The answer is: 3.3333

To get the answer add 2,5 and 3 that is 10 then divide by 3 to get 3.3

Have a nice day

6 0
3 years ago
The melting point of h2o is 0 degrees celsius. this is the same as its:
professor190 [17]
This is the same as its freezing point

hope this helps
6 0
3 years ago
9. Using the balanced equation from Question #8, how many grams of lead will be produced if 2.54 grams of PbS is burned with 1.8
MissTica

Answer: 2.24 grams of Pb

Explanation:

<u>Step 1</u>

Balanced chemical reaction;

2PbS + 3O2 → 2Pb + 2SO3

<u>Step 2</u>

Moles of both PbS and O2

Moles = mass / molar mass

Moles of PbS = 2.54 g / 239.3 g/mol = 0.0108 moles

Moles of O2 = 1.88 / 32 g/mol = 0.0588 moles

<u>Step 3</u>

Finding the limiting reactant.

Limiting reactant, is that reactant which is completely used in the reaction;

If we assume that PbS is the limiting reactant;

We have 0.0588 moles of O2. This needs ( 0.0588 * 2) / 3 = 0.0392 moles of PbS to fully react. But we have only 0.0108 moles of PbS available. That means that the PbS will be completely consumed hence the limiting reactant

If we assume O2 is the limiting reactant;

We have 0.0108 moles of PbS. That needs ( 0.0108 * 3) / 2 = 0.0162 moles of O2. But we have 0.0588 moles of O2 which is in excess further confirming that PbS is the limiting reactant since it will be depleted in the reaction.

<u>Step 4</u>

Moles of lead

For this step we apply the mole ratios with the limiting reactant;

Mole ratio of PbS : Pb = 2 : 2 = 1 : 1

Therefore;

Moles of Pb = (0.0108 moles  * 1 ) 1

Moles of Pb =0.0108 moles

<u>Step 5</u>

Mass of Pb

Mass = moles * molar mass

Mass of Pb =0.0108 moles * 207.2 g/mol

Mass of Pb = 2.24 grams

5 0
2 years ago
Other questions:
  • Which of the following are examples of strong electrolytes?
    5·1 answer
  • What are water droplets at least 0.5 millimeters in diameter?
    7·1 answer
  • Is fermenting wine a chemical or physical change?
    14·1 answer
  • What are the types of radioactive rays that can be produced during a radioactive decay?
    14·1 answer
  • How many moles of NO can be formed when 2.86 mol of N2 reacts?
    11·1 answer
  • In which state do the particles have the most energy?
    14·2 answers
  • Pls answer
    11·2 answers
  • Calculate the number of copper atoms in a 63.55 g<br>sample of copper.​
    8·1 answer
  • A ball has a mass of 2.0 kg and travels a distance of 24 meters in 10 seconds what is the Velocity
    5·1 answer
  • As the atomic number of elements within Group 2 increases, the metallic character of each successive element
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!