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
lawyer [7]
3 years ago
9

Dilution question In many of the experiments, you will be asked to prepare a standard solution by diluting a stock solution. You

will be specifically asked how you will do the dilution steps during the review before you start work. Here is a homework question to get you to think about this process. You have a 1000 ug/mL stock solution of lead (Pb2+). Describe how you would prepare a 100 ppb standard solution from this stock solution. Rules: No single dilution step can be greater than 1:50 You have 25.00 mL volumetric flasks and 10.00 mL volumetric flasks. You have access to three pipet dispensers. One dispenser delivers between 1 and 5 mL, the second dispenser delivers between 100 and 1000 , and the third dispenser delivers between 20 and 200 HL
Chemistry
1 answer:
riadik2000 [5.3K]3 years ago
6 0

Answer:

We could do two 1:50 dilutions and one 1:4 dilutions.

Explanation:

Hi there!

A solution that is 1000 ug/ ml  (or 1000 mg / l) is 1000 ppm.

Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.

Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.

We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):

First step (1:50 dilution):

Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).

Step 2 (1:50 dilution):

Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)

Step 3 (1:4 dilution):

Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.

You might be interested in
PLEASE ANSWER FAST AND YOU WILL GET BRAINLIESTTTTTTT!!!!!!! And POINTSSSSSS!! PLEASE ANSWER FAST AND YOU WILL GET points and BRA
stiks02 [169]

Answer:

B on both questions

Explanation:

6 0
3 years ago
Read 2 more answers
Titration of a 20.0-mL sample of acid rain required 1.7 mL of 0.0811 M NaOH to reach the end point. If we assume that the acidit
Rasek [7]

Answer:

Concentration of sulfuric acid in the acid rain sample is 0.0034467 mol/L.

Explanation:

Volume of NaOH = 1.7 ml = 0.0017 L

Molarity of NaOH = 0.0811 M

Moles of NaOH = n

0.0811 M=\frac{n}{0.0017 L}

n = 0.0001378 mol

H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O

According to reaction, 2 mol of NaOH neutralize 1 mol of sulfuric acid.

Then 0.0001378 mol of NaOH will neutralize:

\frac{1}{2}\times 0.0001378 mol=6.8935\times 10^{-5} mol of sulfuric acid.

Concentration of sulfuric acid in the acid rain sample: x

x=\frac{6.8935\times 10^{-5}}{0.02 L}=0.0034467 mol/L

Concentration of sulfuric acid in the acid rain sample is 0.0034467 mol/L.

7 0
3 years ago
Is sugar (C12H22O11) an element or a compound?
Semmy [17]
I believe that sugar is a compound because there are elements that make up sugar
4 0
3 years ago
Is this True or false?
kherson [118]

Answer:

true

Explanation:

7 0
3 years ago
Read 2 more answers
1. Adakah benar bahawa anda tidak boleh membasuh rambut, meminum air sejuk dan
Ann [662]

Answer:

Adakah benar anda tidak boleh mencuci rambut, minum air sejuk dan

makan ais krim atau bersukan semasa haid? Terangkan jawapan anda.

Tidak, ini tidak benar, melakukan semua ini baik-baik saja. Seperti, tidak ada yang dapat mempengaruhi kita, kerana tidak bersambung dengan sistem kita. Juga, mohon maaf jika bahasa itu salah kerana saya menggunakan terjemahan Google.

Semoga ini membantu :)

7 0
3 years ago
Other questions:
  • A common neutralization reaction, that is used in titrations, involves sodium hydroxide, NaOH, reacting with nitric acid, HNO3.
    6·2 answers
  • Which type of radioactive emission has a positive charge and weak penetrating power?
    11·1 answer
  • Suppose a large atom bonds with a small
    11·1 answer
  • Find the momentum of a 120 g snowball that is rolling with a velocity of 8.9 m/s. Express your answer in two significant figures
    13·1 answer
  • Why foodstuff with acid components should not be stored in aluminium containers why?​
    13·1 answer
  • Gaseous C2H4 reacts with O2 according to the following equation:
    13·2 answers
  • Which of the following best describes where cellular respiration occurs?
    8·2 answers
  • ?
    14·1 answer
  • A 558 mg of a mixture of fluorene and benzoic acid was weighed out and subjected to an extraction and recrystallization. After t
    6·1 answer
  • A reaction vessel for synthesizing ammonia by reacting nitrogen and hydrogen is charged with 5.54 kg of H2 and excess N2. A tota
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!