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
liubo4ka [24]
3 years ago
8

How many moles are in 2.91 X 10^22 atoms of He?

Chemistry
1 answer:
fenix001 [56]3 years ago
4 0

0.048

\\  \\  \\  \\  \\  \\  \\

You might be interested in
What is the quantity of heat evolved when 15g of CH4 is completely burned in air? Given that CH4+2O2→ CO2+2H2OΔH=-890Kj/mol
bagirrra123 [75]

Answer:

You're going to have to convert the grams to moles, and then multiply that with the ratio of heat produced to the ratio of CH4

8 0
3 years ago
Not the best in chemistry please help
aliya0001 [1]
The answer is B the highest point
3 0
3 years ago
Read 2 more answers
In an atomic model that includes a nucleus, positive charge is
olganol [36]
<span>Because protons are positively charged and neutrons have no charge then it is safe to say that such an atomic model would have the positive charge concentrated in the center of an atom (option d).</span>
7 0
3 years ago
Highest energy level for lithium​
Karo-lina-s [1.5K]

<u>Q</u><u>U</u><u>E</u><u>S</u><u>T</u><u>I</u><u>O</u><u>N</u><u> </u><u>:</u>

  • highest energy level for lithium

<u>A</u><u>N</u><u>S</u><u>W</u><u>E</u><u>R</u><u> </u><u>:</u>

  • There are 2 electrons on the first energy level and 1 electron on the second. Explain that the first energy level can only have 2 electrons so the next electron in lithium is on the next (second) level. Explain that neon has 10 protons and 10 electrons.

3 0
3 years ago
Calculate the pH of the following simple solutions:
IceJOKER [234]

Answer :

(1) pH = 1.27

(2) pH = 13.35

(3) The given solution is not a buffer.

Explanation :

<u>(1) 53.1 mM HCl</u>

Concentration of HCl = 53.1mM=53.1\times 10^{-3}M

As HCl is a strong acid. So, it dissociates completely to give hydrogen ion and chloride ion.

So, Concentration of hydrogen ion= 53.1\times 10^{-3}M

pH : It is defined as the negative logarithm of hydrogen ion concentration.

pH=-\log [H^+]

pH=-\log (53.1\times 10^{-3})

pH=1.27

<u>(2) 0.223 M KOH</u>

Concentration of KOH = 0.223 M

As KOH is a strong base. So, it dissociates completely to give hydroxide ion and potassium ion.

So, Concentration of hydroxide ion= 0.223 M

Now we have to calculate the pOH.

pOH=-\log [OH^-]

pOH=-\log (0.223)

pOH=0.65

Now we have to calculate the pH.

pH+pOH=14\\\\pH=14-pOH\\\\pH=14-0.65=13.35

<u>(3) 53.1 mM HCl + 0.223 M KOH</u>

Buffer : It is defined as a solution that maintain the pH of the solution by adding the small amount of acid or a base.

It is not a buffer because HCl is a strong acid and KOH is a strong base. Both dissociates completely.

As we know that the pH of strong acid and strong base solution is always 7.

So, the given solution is not a buffer.

5 0
3 years ago
Other questions:
  • A hydrate is determined to be 45.43% water and 54.57% CoCl. Find the chemical formula and name
    10·1 answer
  • What is the oxidation number for ba??
    9·1 answer
  • The nucleus of some isotopes will spontaneously undergo nuclear decay. These isotopes are said to be radioactive. What causes th
    12·2 answers
  • Aside from Earth, which of the following inner planets once had liquid water on its surface?
    9·2 answers
  • BRAINLIEST
    6·1 answer
  • During the winter months, many locations experience snow and ice storms. It is a common practice to treat roadways and sidewalks
    6·1 answer
  • What is the formula of Barium Carbonate?​
    14·2 answers
  • Determine the number of moles in 5.25x1024 formula units if lead (IV) oxide.
    8·1 answer
  • Of sulfuric acid, carbonic acid, nitric acid, and hydrochloric acid, which one is considered a weak acid
    10·2 answers
  • Determine the partial pressure and number of moles of each gas in a 15.75-L vessel at 30.0 C containing a mixture of xenon and n
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!