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
Salsk061 [2.6K]
3 years ago
12

Tris is a molecule that can be used to prepare buffers for biochemical experiments. It exists in two forms: Tris (a base) and Tr

isH (an acid). The MW of Tris base is 121.14 g/mol; the MW of TrisH is 157.6 g/mol (the extra weight is due to the Cl- counterion that is present in the acid). The Ka of the acid is 8.32 X 10-9. Assume that you have TrisH in solid form (a powder), unlimited 1M HCl, 1 M NaOH and distilled water. How would you prepare 1 L of a 0.02 M Tris Buffer, pH?
Chemistry
1 answer:
ale4655 [162]3 years ago
3 0

Solution :

For the reaction :

$\text{TrisH}^+ + H_2O \rightarrow \text{Trish}^- + H_3O^+$

we have

$Ka = \frac{[\text{Tris}^- \times H_3O]}{\text{Tris}^+}$

   $=\frac{x^2}{0.02 -x}$

  $=8.32 \times 10^{-9}$

Clearing $x$, we have $x = 1.29 \times 10^{-5} \text{ moles of acid}$

So to reach $\text{pH} = 7.8 (\text{pOH}= 14-7.8=6.2)$, one must have the $\text{OH}^-$ concentration of the :

$\text{[OH}^-]=10^{-pOH} = 6.31 \times 10^{-7} \text{ moles of base}$

So we can add enough of 1 M NaOH in order to neutralize the acid that is calculated above and also adding the calculated base.

$\text {n NaOH}=1.29 \times 10^{-5}+6.31 \times 10^{-7}$

            $= 1.35 \times 10^{-5} \text{ moles}$

Volume NaOH $= 1.35 \times 10^{-5} \text{ moles} \times \frac{1000 \text{ mL}}{1 \text{ mol}} = 0.0135 \text{ mL}$

Tris mass $H^+ = 0.02 \text{ mol} \times 157.6 \text{ g/mol}=3.152 \text{ g}$

Now to prepare the said solution we must mix:

$3.152 \text{ g Tris H} + 0.0135 \text{ mL NaOH} \ 1 M$ gauge to 1000 mL with water.

You might be interested in
6. The fusion of 4 H-1 nuclei to produce two positrons and one other nuclei.​
KIM [24]

Explanation:

Normally, fusion involves two heavy hydrogen nuclides but since we have 4 light hydrogen nuclides, two of which underwent positron emission, thus changing two protons into neutrons plus 2 positrons and 2 neutrinos. The resulting nucleus from this fusion reaction is an He-4 nucleus.

3 0
3 years ago
4) How many grams are there in 7.40 moles of AgNO3
Ludmilka [50]

Answer:

1260 grams

Explanation:

3 0
3 years ago
How do mutualism and parasitism compare
Trava [24]
A) would be the only correct one from my knowledge. Mutualism is when neither Organism is harmed and both live mutually together, and Parasitism is when an Organism is living on the, ex. nutrients, of the host.
6 0
3 years ago
Read 2 more answers
Balance this equation please.
forsale [732]
2K + 2H2O = 2KOH + H2
6 0
4 years ago
Read 2 more answers
Explain the regiochemistry of the Friedel-Crafts alkylation of 1,4-dimethoxybenzene. There are three positions available for the
defon

Answer:

In an electrophilic aromatic substitution (Friedel Crafts alkylation) first in the monoalkylation of the 1,4-dimethoxybenzenethe the methoxy groups redirects the substitution for ortho-para positions with respect to the electrophile that is going to enter (alkyl group) this is due to the increase in electron density in that position, that is , to the inductive effect.

According to the second incoming alkyl group there would be 3 positions available, from which it will choose the meta position in relation to the second methoxy group, since the alkyl group is a weak activator of the ortho meta positions and coincides with the position to which it redirects the second methoxy group.

7 0
3 years ago
Other questions:
  • How could you interpret the events taking place on a molecular level in the images seen here? A) Kinetic energy decreases from l
    7·2 answers
  • For each equation , write all possible mole ratios . A. 2HgO(s)>2Hg(l)+O2(g) B. 4NH3(g)+6NO(g)>5N2(g)+6H2O(l)
    5·2 answers
  • Compare and contrast mutualism and commnsalism. For both relationships, explain who does or does not benefit and who is or is no
    5·1 answer
  • At a certain temperature the vapor pressure of pure heptane (C_7 H_16) is measured to be 170. torr. Suppose a solution is prepar
    7·1 answer
  • The half‑equivalence point of a titration occurs half way to the equivalence point, where half of the analyte has reacted to for
    9·1 answer
  • PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    9·1 answer
  • Explain why the speed of sound is faster in solids than in gases. Include two other factors Chapter 17 says the speed of sound c
    11·2 answers
  • How does the location and design of a house can help control temperature?
    12·1 answer
  • A flask containing a volume of 180 L of bromine was collected under a pressure of 35.5 kPa. What pressure would have been requir
    14·1 answer
  • Solution X is saturated at 40 g per 100 g of water. If 45 g of X is
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!