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
Anton [14]
3 years ago
11

How many moles are in 2.31*10^21 atoms of lead

Chemistry
1 answer:
Anon25 [30]3 years ago
6 0
Hey there!:

Molar mass Lead  ( Pb ) = 207.2 g/mol

Therefore:

1 mole Pb --------------------- 6.02*10²³ atoms
? moles Pb -------------------- 2.31*10²¹ atoms

moles Pb = ( 2.31*10²¹ ) * 1 / ( 6.02*10²³ ) = 

moles Pb = ( 2.31*10²¹ ) / ( 6.02*10²³ ) = 

=> 0.00383 moles of Pb

Hope this helps ! 
You might be interested in
A sample of barium nitrate is placed into a jar containing water. The mass of the barium nitrate sample is 27g. Assume the water
34kurt
So we have Barium nitrate with a solubility of 8.7g in 100g water at 20°C.

using that relation
i.e.
8.7g (barium nitrate) =100g (water)
1g barium nitrate = 100/8.7 g water

27g barium nitrate = (100/ 8.7 ) × 27
= 310.34 g

therefore,
you need 310.34g of water is in the jar.

5 0
3 years ago
Read 2 more answers
Plastic is used for making a large variety of articles of daily use and these articles are very attractive. But it is advised to
boyakko [2]

Answer:

please select my answer as brainlist answers

Explanation:

plastic is harmful for the environment

4 0
3 years ago
Read 2 more answers
Elements that do not have full outer electron shells will donate, share, or take from other atoms. Choose the items that have th
Gnesinka [82]

Answer:

Ok...

Answer: YTH/JYG

Explanation:

AI+ZN+H=YTH

7 0
3 years ago
A particular element found in nature exists as two stable isotopes. 60.4% of the element has a mass of 68.9257amu, the rest of t
miss Akunina [59]
Mass           %abundance        # of atoms (pick 1000 sample)
68.9257         60.4%                  604
70.9249         39.6%                  396
*39.6* ( i got this by subtracting 100 as most percentage is out of 100)
*# of atoms* ( i just moved it one decimal place, then i am going to make the sample out of 1000, to get the decimal place)

Formula= total mass/ total #atoms

x= (68.9257u* 604) + (70. 9249*396)/ 1000
x- 69717. 3832/ 1000
x= 69.717amu or 69.72 amu 

if you look on the periodic table the closet element with that mass is gallium ( amu is 69.72)
6 0
3 years ago
calculate the number of grams of CH3COONa * 3H2O (sodium acetate tri-hydrate) needed to make 250.0 mL of a CH3COOH (acetic acid)
anastassius [24]

Answer:

10.88 g

Explanation:

We have:                            

[CH₃COOH] = 0.10 M

pH = 5.25

Ka = 1.80x10⁻⁵      

V = 250.0 mL = 0.250 L

M_{CH_{3}COONa*3H_{2}O} = molar \thinspace mass = 136 g/mol

The pH of the buffer solution is:  

pH = pKa + log(\frac{[CH_{3}COONa*3H_{2}O]}{[CH_{3}COOH]})    (1)

By solving equation (1) for [CH₃COONa*3H₂O] we have:  

log [CH_{3}COONa*3H_{2}O] = pH - pKa + log [CH_{3}COOH]  

log [CH_{3}COONa*3H_{2}O] = 5.25 - (-log(1.80 \cdot 10^{-5})) + log (0.10) = -0.495                                

[CH_{3}COONa*3H_{2}O] = 10^{-0.495} = 0.32 M

Hence, the mass of the sodium acetate tri-hydrate is:

m = moles*M = [CH_{3}COONa*3H_{2}O]*V*M = 0.32 mol/L*0.250 L*136 g/mol = 10.88 g

Therefore, the number of grams of CH₃COONa*3H₂O needed to make an acetic acid/sodium acetate tri-hydrate buffer solution is 10.88 g.

I hope it helps you!      

4 0
3 years ago
Other questions:
  • The atomic mass of H2 SO4
    13·1 answer
  • Explain why lunar eclipses are more common than solar eclipses and why so few people ever have a chance to view a total solar ec
    13·1 answer
  • Which of the following measurements is used to compare the distance between objects in the solar system?
    8·2 answers
  • Hydroelectric power plants capture the ______________ of falling water to generate electricity. The falling water turns a wheel
    13·1 answer
  • <img src="https://tex.z-dn.net/?f=plz%20%5C%3A%20help%20%20%5C%3A%20me%20%5C%3A%20it%20%5C%3A%20is%20%5C%3A%20due%20%5C%3A%202mo
    10·1 answer
  • Pls help what the ratio ?.<br>enter your answer as an integer ​
    7·1 answer
  • Electron X can change to a higher energy level or a lower energy level. Which statement is true of electron X?
    12·1 answer
  • Which is NOT a common property of a metal?
    10·2 answers
  • The Gulf Stream flows along the equator before turning north along Florida’s east coast. How does the Gulf Stream impact Florida
    7·2 answers
  • what is the atomic number of an element with a atomic weight of 77cwnd 55 neutrons? Please help fast!
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!