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
Los campers ________ por un parque cerca del camping. Question options: dan una caminata se duermen toman una ducha
zvonat [6]

Answer:

dan una caminata

Explanation:

3 0
3 years ago
Consider the cell described below at 259 K: Ni | Ni2+ (1.15 M) || Fe3+ (2.23 M) | Fe Given the standard reduction potentials fou
likoan [24]

Answer:

i dont know sorry :(

Explanation:

8 0
3 years ago
If solid iron is dropped in liquid iron, it will most likely?
S_A_V [24]

it will sink

Explanation:

the solid iron will sink because it is dense than the liquid iron I will sink and it will melt

4 0
3 years ago
Read 2 more answers
In cucumbers, green skin (G) is dominant to striped skin (g). If a farmer crosses a heterozygous (hybrid) cucumber with a homozy
Elena L [17]

Answer:

Half will be green and half will be striped

Explanation:

Given green skin (G) is dominant to striped skin (g).

Cucumber 1 : Heterozygous (Gg)

Cucumber 2 : Homozygous striped (gg)

When Gg X gg :

     G      g

g   Gg   gg

g   Gg   gg

Half of the offspring will have Gg genotype so they will be green. Other half will have gg genotype so they will be striped.

8 0
3 years ago
I need help with this please
jarptica [38.1K]

Answer: the place that i put the letters is how it should look also 75% of your peas are green

Explanation:

3 0
3 years ago
Other questions:
  • A gas has a volume of 25.6 L at a temperature of 278 K. What will be the new temperature, in C, if
    14·1 answer
  • How many elements are there in mint chocolate chip ice cream?
    9·1 answer
  • What I said the molarity of an hcl solution if 24.0 ml is completely neutralized by 98.0 ml of 0.250m ca(oh)2
    10·1 answer
  • Predict what might happen if the human body did not have specialized cells, tissues, organs, and organ systems to maintain homeo
    10·2 answers
  • Phosphoric acid is a triprotic acid with the following pKa values:pKa1=2.148, pKa2=7.198, pKa3=12.375You wish to prepare 1.000 L
    12·1 answer
  • A sample of pure NH4HS is placed in a sealed 2.0-L container and heated to 550 K at which the equilibrium constant is 3.5 x 10-3
    15·1 answer
  • Can someone please name a project I can do for my science fair for 7th grade I need a easy one
    6·1 answer
  • Hydroxyl, ether, carbonyl, or amine?
    8·1 answer
  • HNS + O2 =<br><br> How do I balance this equation?
    15·2 answers
  • heeellllllllllllllllllllllpppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!