A gas occupies a 1.5 l container at 25 degrees

The images show two unrelated events occurring at separate times.

trapecia [35]

Event 1 is an example of a chemical reaction.

Explanation:

Whenever if two solutions are mixed, then if there is any color change, or evolution of any vapors, bubbles or gas formation or if there is any formation of a color or white precipitate confirms that the occurrence of a chemical reaction.

If nothing happens said above then it is said that there is no chemical reaction occurs.

Here in the event 1 a clear liquid in one beaker poured into clear liquid in beaker 2 then there is a formation of orange liquid, which means there is a formation of a new colored liquid confirms that the chemical reaction occurred.

4 0

3 years ago

Read 2 more answers

After performing a dilution calculation, you determine you need 25.0 milliliters of an aqueous stock solution to make 100.0 mill

IRINA_888 [86]

A is obviously out because it leads to a volume of 125.0 milliliters of the new solution and gives you a lower concentration than you were aiming for.

D is out because you are adding 75 milliliters of the stock solution, so your concentration would be too high. You only need 25.0 milometers of stock solution per 100 milliliters of the new solution.

C is also out because it leads to 50.0 milliliters stock solution per 100 milliliters of the new solution and hence the wrong concentration.

B is by default the correct answer. It also details the correct technique. First you add the stock solution (This you know from your calculations to be 25 milliliters.) then you add the water up to the volume you needed. (Because the calculations only tell you the total volume of water not what you need to add) You also add the water last so you can rinse the neck of the flask to make sure you also get all the stock solution residue into the stock solution.

I would add the final step of stirring, but B is the only answer that can be correct.

8 0

4 years ago

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How much iodine (I2), in grams, should be added to water to produce 2.5L of solution with a molarity of 0.56M?

denis-greek [22]

Molarity=Moles of solute/Volume of solution in L

So

0.56M=moles/2.5L
moles=0.56(2.5)
moles of Iodine=1.4mol

Mads of Iodine

Moles(Molar mass)
1.4(126.9)
177.66g

7 0

2 years ago

When calcium metal (Ca) reacts with oxygen gas (O2), it produces the ionic compound calcium oxide (CaO). Write the balanced equa

malfutka [58]

The balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

and

The process meets the requirements to be considered a redox reaction.

From the question,

We are to write a balanced chemical equation for the reaction between Calcium metal and oxygen gas

The balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

This is the balanced chemical equation for the reaction

To determine whether the reaction meets the requirements to be considered a redox reaction,

We will define the term redox reaction

A redox reaction, also called oxidation-reduction reaction, is any chemical reaction in which the oxidation number of a participating chemical species changes.

From the balanced equation above we can observe that the oxidation number of the participating species(Calcium and oxygen) changed.

The oxidation number of Calcium changed from 0 to +2

and

The oxidation number of Oxygen changed from 0 to -2

∴ The process meets the requirements to be considered a redox reaction.

Hence, the balanced chemical equation for the reaction is

2Ca(s) + O₂(g) → 2CaO(s)

and

The process meets the requirements to be considered a redox reaction.

Learn more here: brainly.com/question/17716543

7 0

2 years ago

In a fluorine atom, on which energy level are the valence electrons found?

aivan3 [116]

Answer:

second energy level

Explanation:

Valence electrons are those electrons which are present in outer most orbital of the atom.

This can be easily found through the electronic configuration of atom.

Electronic configuration of F:

F₉ = 1s² 2s² 2p⁵

We can see that the valence electrons are present in second energy level of F atom.

There are seven valence electrons of fluorine.

It is called halogens.

Halogens are very reactive these elements can not be found free in nature. Their boiling points also increases down the group which changes their physical states. i.e fluorine is gas while iodine is solid.

Fluorine:

1. it is yellow in color.

2. it is flammable gas.

3. it is highly corrosive.

4. fluorine has pungent smell.

5. its reactions with all other elements are very vigorous except neon, oxygen, krypton and helium.

6 0

3 years ago