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
BabaBlast [244]
2 years ago
9

What is biological oxygen demand

Chemistry
2 answers:
Novosadov [1.4K]2 years ago
7 0
<span> is the amount of </span>dissolved oxygen<span> needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period. </span>
jek_recluse [69]2 years ago
5 0

Hey there!!

Biological Oxygen demand is the amount of dissolved oxygen needed  by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

Hope this helped you and have a fantastic day! (:

You might be interested in
Acetone (nail polish remover) has a density of 0.7857 g &gt;cm3.
Stella [2.4K]

If acetone has a density of 0.7857 \frac{g}{cm^{3} }  the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.

<h3>What is acetone?</h3>

Acetone is known as a chemical substance that is usually found in the environment but can also be produced artificially. Acetone is a polar organic product that interacts very well with water molecules, generating dipole-dipole relationships.It is colorless with a distinctive smell and taste, we find it in products known as <u>cleaning and personal care products</u>, but we can also use it as a solvent for substances.

Also in the environment in <u>plants, trees and in volcano emissions or in forest fires</u>, it does not become <em>toxic</em> in low doses but if it is exposed to an individual in high doses it can become <em>fatal</em>.

In the statement we can find that acetone has a density of 0.7857 \frac{g}{cm^{3} }.

Therefore, we can confirm that if acetone has a density of 0.7857 \frac{g}{cm^{3} }  the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.

To learn more about acetone visit: brainly.com/question/13334667?referrer=searchResults

#SPJ1

7 0
2 years ago
Whats the complete chemical symbol for the ion that has : 13 neutrons 11 protons , and 9 electrons.
myrzilka [38]
The answer gonna be Na2+
7 0
3 years ago
Chemistry Lab Question: Filtration
tatyana61 [14]

For the first question, salt is soluble while sand is insoluble or not dissolvable in water. The salt should have vanished or melted, but the sand stayed noticeable or visible, making a dark brown solution probably with some sand particles caught on the walls of the container when the boiling water was put in to the mixture of salt and sand. The solubility of a chemical can be disturbed by temperature, and in the case of salt in water, the hot temperature of the boiling water enhanced the salt's capability to melt in it.

For the second question, the melted or dissolved salt should have easily made its way through the filter paper and into the second container, while the undissolved and muddy sand particles is caught on the filter paper. The size of the pores of the filter paper didn’t change. On the contrary, the size of the salt became smaller because it has been dissolved which is also the reason why it was able to go through the filter paper, while the size of the sand may have doubled or even tripled which made it harder to pass through.

6 0
3 years ago
If nitrogen (N) has 2 naturally occurring isotopes, nitrogen-14 (78.3%) and nitrogen-16 (21.7%), what is its average r.a.m.?
leva [86]

Answer:

14.434 r.a.m.

Explanation:

  • The atomic mass of an element is a weighted average of its isotopes in which the sum of the abundance of each isotope is equal to 1 or 100%.

∵ The atomic mass of N = ∑(atomic mass of each isotope)(its abundance)

∴ The atomic mass of N = (atomic mass of N-14)(abundance of N-14) + (atomic mass of N-16)(abundance of N-16)

atomic mass of N-14 = 14.0 r.a.m, abundance of N-14 = percent of N-14/100 = 78.3/100 = 0.783.

atomic mass of N-16 = 16.0 r.a.m, abundance of N-16 = percent of N-16/100 = 21.7/100 = 0.217.

∴ The atomic mass of N = (atomic mass of N-14)(abundance of N-14) + (atomic mass of N-16)(abundance of N-16) = (14.0 r.a.m)(0.783) + (16.0 r.a.m)(0.217) = 14.434 r.a.m.

5 0
3 years ago
How many moles are contained in 2.0 L of N2 at standard temperature and pressure.
GuDViN [60]

0.091 moles are contained in 2.0 L of N2 at standard temperature and pressure.

Explanation:

Data given:

volume of the nitrogen gas = 2 litres

Standard temperature = 273 K

Standard pressure = 1 atm

number of moles =?

R (gas constant) = 0.08201 L atm/mole K

Assuming nitrogen to be an ideal gas at STP, we will use Ideal Gas law

PV = nRT

rearranging the  equation to calculate number of moles:

PV = nRT

n = \frac{PV}{RT}

putting the values in the equation:

n = \frac{1X2}{0.08201 X 273}

n = 0.091 moles

0.091 moles of nitrogen gas is contained in a container at STP.

6 0
3 years ago
Other questions:
  • When ch4(g) reacts with h2o(g) to form h2(g) and co(g), 206 kj of energy are absorbed for each mole of ch4(g) that reacts. write
    9·1 answer
  • An element's atomic number is 78. How many protons would an atom of this element have?
    13·1 answer
  • Nitric oxide is formed in automobile exhaust when nitrogen and oxygen in air react at high temperatures.N2(g) + O2(g) 2NO(g)The
    8·1 answer
  • What human activities have change earth
    12·1 answer
  • Which pair below describes isotopes of the same element?
    8·2 answers
  • Which of the following represents a compound made of five molecules? CO 5 C 2O 5 C 5O 5CO 2
    8·1 answer
  • Rubidium has an atomic number of 37 and a mass number of 85. How many protons, neutrons, and electrons does an ion of rubidium w
    7·1 answer
  • 2) Imagine that a loudspeaker is producing quiet note with a low pitch
    6·1 answer
  • What is the volume of 0.98 mol oxygen gas at 275 k and a pressure of 2.0 atm
    9·1 answer
  • omplete the relationship between ph and pka for each of the following atomic view pictures of a buffered solution.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!