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
Fantom [35]
2 years ago
13

Which of these scientists diagnosed smallpox and measles?

Chemistry
1 answer:
kotykmax [81]2 years ago
5 0
......................B. Al-Razi
You might be interested in
Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic
ale4655 [162]

A) 10.75 is the concentration of arsenic in the sample in parts per billion .

B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)It will take 1.37 years to remove all of the arsenic from the lake.

Explanation:

A) Mass of arsenic in lake water sample = 164.5 ng

The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.

To calculate the ppm of oxygen in sea water, we use the equation:

\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9

Both the masses are in grams.

We are given:

Mass of arsenic = 164.5 ng = 164.5\times 10^{-9} g

1 ng=10^{-9} g

Volume of the sample = V = 15.3 cm^3

Density of the lake water sample ,d= 1.00 g/cm^3

Mass of sample =  M = d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g

ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75

10.75 is the concentration of arsenic in the sample in parts per billion.

B)

Mass of arsenic in 1 cm^3  of lake water = \frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g

Mass of arsenic in 0.710 km^3 lake water be m.

1 km^3=10^{15} cm^3

Mass of arsenic in 0.710\times 10^{15} cm^3 lake water :

m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g

1 g = 0.001 kg

7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg

7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

\frac{2.74}{41.90} days

Then days required to remove 7,633.66 kg of arsenic from the lake water :

=7,633.66\times \frac{2.74}{41.90} days=499.19 days

1 year = 365 days

499.19 days = \frac{499.19}{365} years = 1.367 years\approx 1.37 years

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

\frac{2.74}{41.90} days

Then days required to remove 7,633.66 kg of arsenic from the lake water :

=7,633.66\times \frac{2.74}{41.90} days=499.19 days

1 year = 365 days

499.19 days = \frac{499.19}{365} years = 1.367 years\approx 1.37 years

It will take 1.37 years to remove all of the arsenic from the lake.

6 0
2 years ago
If the pH is 9 what is the concentration of hydroxide ion [OH]? (hint: find the pOH first)
UkoKoshka [18]
Realize that pH + pOH = 14
so, 9 + pOH = 14 -> pOH = 5
pOH = -log[OH-]
5 = -log[OH-]
plug it into a calculator and you get 1.0 x 10^-5
alternatively, use [OH-] = 10^-pOH to get the same answer
[OH-] = 1.0 x 10^-5
6 0
2 years ago
Read 2 more answers
Look at the table. Which of these three substances is not an alloy?
Gemiola [76]

Answer:

B is the correct option.

5 0
2 years ago
Read 2 more answers
“NH4VO3” is a... <br><br> Symbol <br><br><br> Name <br><br><br> Chemical formula
shepuryov [24]

Answer:

its a chemical formula, it has numbers and symbols

3 0
3 years ago
Read 2 more answers
Hypothesize!​ What type of substance do you think Coffee is? Why?
Serhud [2]
brainly.com/question/4911981
4 0
2 years ago
Read 2 more answers
Other questions:
  • How did convection currents cause the plates to move
    13·1 answer
  • Which elements properties form the basis for all life
    5·2 answers
  • How does thermal energy transfer when a room is heated by a furnace?
    5·1 answer
  • Which is a chemical property of iron?
    11·2 answers
  • A. When ammonium nitrate (NH4NO3) explodes, the products are nitrogen, oxygen, and water. When 40 grams of ammonium nitrate expl
    12·2 answers
  • An atom of a particular element has a volume of 7.8x10^-31 m^3. What is this volume in cubic nanometers
    5·1 answer
  • How many totals atoms are in 2Ba(No3)3
    14·1 answer
  • Given that XeF4 reacts with water to form explosive XeO3, chemists would not handle it near water. However, why would you still
    9·1 answer
  • A race car driver pulls onto a circular track. After 10 seconds, his speed is 200 km/h. The car travels at a steady speed of 200
    5·1 answer
  • Which substance is not a solid at 20˚C and one atmosphere of pressure?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!