What does is so used to eliminate a substance that is too large to leave by diffusion

What three things happen in order for a chemical reaction to occur?

MissTica

Three things that should happen for a chemical reaction to occure :
1. Position of electrons must change
2. Chemical bonds must be formed and broken between atoms and
3. No changes should happen to the nuclei

4 0

3 years ago

Darwin's theorized that three conditions were necessary for natural selection to occur, which of the following is NOT one of the

Mekhanik [1.2K]

Answer:

The correct option is: stable environment

Explanation:

According to the Darwin's theory, natural selection is the concept by which all the small useful variations of traits are preserved.

According to Darwin, there are three necessary and sufficient conditions for the occurrence of natural selection:

1. struggle for existence

2. variation

3. inheritance

These conditions are said to be necessary because if these conditions are not satisfied then natural selection does not occur.

These conditions are said to be sufficient because if these conditions are satisfied, then natural selection will most definitely occur.

8 0

3 years ago

Write the complete balanced equation for the neutralization reaction that occurs when aqueous hydroiodic acid, HI, and sodium hy

Serhud [2]

Answer:

H+ ( aq ) + HCO3- ( aq ) ------> H2O( l ) + CO2 ( g )

Explanation:

The complete reaction when hydroiodic acid and sodium hydrogen carbonate combine, would be as follows -

HI + NaHCO3 ----> NaI + H2O + CO2

net reaction

H2CO3 is highly unstable, and thus decomposes into the water and carbon dioxide you see present as the reactants. If you didn't know already, H2CO3 is also reffered to as carbonic acid. The rest of the elements present on the reactant side are Iodine and Sodium, which is why they are present on the product side as NaI.

Let me include the " physical states " in this reaction as well -

HI ( aq ) + NaHCO3 ( aq ) ----> NaI ( aq ) + H2O ( l ) + CO2 ( g )

Now the complete ionic equation would simply be each compound present as ions in an aqueous solution, so there is no need for an explanation on this step -

H+ ( aq ) + I- ( aq ) + Na+ ( aq ) + HCO3- ( aq ) -------> Na+ ( aq ) + I- ( aq ) + H2O( l ) + CO2 ( g )

The spectator ions in this reaction are I- and Na+, so canceling them out, you would receive the following net ionic equation -

H+ ( aq ) + HCO3- ( aq ) ------> H2O( l ) + CO2 ( g )

Hope that helps!

4 0

3 years ago

Kaila runs competitively. She would like to calculate her average running speed each time she runs. Which data should Kaila reco

Sladkaya [172]

Answer:

Start and end times; distance run.

Step-by-step explanation:

Average speed = distance/time.

Kaila should record the distance run, the time she started, and the time she ended her run.

The difference between the start and end times gives the time for the run.

If she inserts her numbers into the formula, she will get her average running speed.

4 0

4 years ago

a gas that exerts a pressure of 215 torr in a container with a volume of 51.0 mL will exert a pressure of ? torr when transferre

zhannawk [14.2K]

To calculate the new pressure, we can use Boyle’s law to relate these two scenarios (Boyle’s law is used because the temperature is assumed to remain constant). Boyle’s law is:

P1V1 = P2V2,

Where “P” is pressure and “V” is volume. The pressure and volume of the first scenario is 215 torr and 51 mL, respectively, and the second scenario has a volume of 18.5 L (18,500 mL) and the unknown pressure - let’s call that “x”. Plugging these into the equation:

(215 torr)(51 mL) =(“x” torr)(18,500 mL)
x = 0.593 torr

The final pressure exerted by the gas would be 0.593 torr.

Hope this helps!

3 0

4 years ago