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
irinina [24]
3 years ago
12

How many moles of helium atoms are there in

Chemistry
1 answer:
fredd [130]3 years ago
6 0

a is the correct answer .

2.4 × 10^24

You might be interested in
The addition of phosphate to a chemical compound is called A. glycolysis. B. oxidation. C. reduction. D. phosphorylation.
stich3 [128]

Answer:

Option (D)

Explanation:

Phosphorylation can be simply defined as the addition of a phosphate group to an organic and inorganic molecule. This process helps in regulating the processes that occur in the cells. It leads to the growth and development of cells and this process is efficiently carried out with the help of enzymes like kinase. It also plays an important role in transferring the signals within the cells, synthesis, and functioning of proteins within the cells, and storing as well as releasing of energy.

Thus, the correct answer is option (D).

5 0
3 years ago
Phases of Matter Activity okay i have to make some dumb comic but i cant draw and am really dumb, but can someone do it for me i
Darya [45]

Answer:

#if u think ur a dumb thn u'll always b a dumb so try it urself n don't think ur a dumb n one more l don't want ur crown if u don't like my ans....  ;)

6 0
3 years ago
A container of hydrogen gas has the same temperature as a container of oxygen gas. The gas atoms having the greater average kine
user100 [1]

Answer:

hope this helps

Explanation:

The atoms of hydrogen have smaller mass than oxygen. Thus their speeds have to higher in order to produce the same average kinetic energies.

4 0
2 years ago
Benzoic acid is a natural fungicide that naturally occurs in many fruits and berries. The sodium salt of benzoic acid, sodium be
AlexFokin [52]

Answer:

a. pH = 2.52

b. pH = 8.67

c. pH = 12.83

Explanation:

The equation of the titration between the benzoic acid and NaOH is:

C₆H₅CO₂H + OH⁻ ⇄ C₆H₅CO₂⁻ + H₂O    (1)

a. To find the pH after the addition of 20.0 mL of NaOH we need to find the number of moles of C₆H₅CO₂H and NaOH:

\eta_{NaOH} = C*V = 0.250 M*0.020 L = 5.00 \cdot 10^{-3} moles

\eta_{C_{6}H_{5}CO_{2}H}i = C*V = 0.300 M*0.050 L = 0.015 moles  

From the reaction between the benzoic acid and NaOH we have the following number of moles of benzoic acid remaining:

\eta_{C_{6}H_{5}CO_{2}H} = \eta_{C_{6}H_{5}CO_{2}H}i - \eta_{NaOH} = 0.015 moles - 5.00 \cdot 10^{-3} moles = 0.01 moles

The concentration of benzoic acid is:

C = \frac{\eta}{V} = \frac{0.01 moles}{(0.020 + 0.050) L} = 0.14 M

Now, from the dissociation equilibrium of benzoic acid we have:

C₆H₅CO₂H + H₂O ⇄ C₆H₅CO₂⁻ + H₃O⁺  

0.14 - x                            x                x

Ka = \frac{[C_{6}H_{5}CO_{2}^{-}][H_{3}O^{+}]}{[C_{6}H_{5}CO_{2}H]}

Ka = \frac{x*x}{0.14 - x}

6.5 \cdot 10^{-5}*(0.14 - x) - x^{2} = 0   (2)  

By solving equation (2) for x we have:          

x = 0.0030 = [C₆H₅CO₂⁻] = [H₃O⁺]

Finally, the pH is:

pH = -log([H_{3}O^{+}]) = -log (0.0030) = 2.52

b. At the equivalence point, the benzoic acid has been converted to its conjugate base for the reaction with NaOH so, the equilibrium equation is:

C₆H₅CO₂⁻ + H₂O  ⇄  C₆H₅CO₂H + OH⁻     (3)

The number of moles of C₆H₅CO₂⁻ is:

\eta_{C_{6}H_{5}CO_{2}^{-}} = \eta_{C_{6}H_{5}CO_{2}H}i = 0.015 moles

The volume of NaOH added is:

V = \frac{\eta}{C} = \frac{0.015 moles}{0.250 M} = 0.060 L

The concentration of C₆H₅CO₂⁻ is:

C = \frac{\eta}{V} = \frac{0.015 moles}{(0.060 L + 0.050 L)} = 0.14 M

From the equilibrium of equation (3) we have:

C₆H₅CO₂⁻ + H₂O  ⇄  C₆H₅CO₂H + OH⁻  

0.14 - x                              x               x

Kb = \frac{[C_{6}H_{5}CO_{2}H][OH^{-}]}{[C_{6}H_{5}CO_{2}^{-}]}

(\frac{Kw}{Ka})*(0.14 - x) - x^{2} = 0

(\frac{1.00 \cdot 10^{-14}}{6.5 \cdot 10^{-5}})*(0.14 - x) - x^{2} = 0

By solving the equation above for x, we have:

x = 4.64x10⁻⁶ = [C₆H₅CO₂H] = [OH⁻]

The pH is:

pOH = -log[OH^{-}] = -log(4.64 \cdot 10^{-6}) = 5.33

pH = 14 - pOH = 14 - 5.33 = 8.67

     

c. To find the pH after the addition of 100 mL of NaOH we need to find the number of moles of NaOH:

\eta_{NaOH}i = C*V = 0.250 M*0.100 L = 0.025 moles

From the reaction between the benzoic acid and NaOH we have the following number of moles remaining:                              

\eta_{NaOH} = \eta_{NaOH}i - \eta_{C_{6}H_{5}CO_{2}H} = 0.025 moles - 0.015 moles = 0.010 moles                          

The concentration of NaOH is:

C = \frac{\eta}{V} = \frac{0.010 moles}{0.100 L + 0.050 L} = 0.067 M

Therefore, the pH is given by this excess of NaOH:         

pOH = -log([OH^{-}]) = -log(0.067) = 1.17

pH = 14 - pOH = 12.83

I hope it helps you!    

4 0
3 years ago
An ion from a given element has 24 protons and 22 electrons
musickatia [10]
Hi,

An ion with unequal number of protons and electrons haves a name. A name depends on whether there are more protons than electrons (CATION) or if there are more electrons than protons (ANION).

Hope this helps.
r3t40
8 0
3 years ago
Other questions:
  • The concentration of sugar in a soft drink is measured to be 10.5%. how many grams of sugar are in 125 g of the drink?
    7·1 answer
  • What are the empirical formulas of c4h10<br>c2h5oh <br>h2s2o8 <br>b2h6 <br>please 
    9·1 answer
  • Please help I will reward Brainly
    13·2 answers
  • If you measured 25 g jelly beans and 25 g of
    10·2 answers
  • What mineral is not a structural component of bone?
    13·1 answer
  • Please answer fast and correct. (15 points)
    11·2 answers
  • 13. "The business of America is business.” — President Calvin Coolidge.
    15·1 answer
  • Fill in the blank ......
    9·2 answers
  • Which type of prevailing wind would carry more water vapor (humidity)? (Choose one)
    13·1 answer
  • 1.) The following is a close view of particle movements. Which state of<br> matter are you viewing?"
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!