Plant cell synthesize energy rich organic molecules and later energy is released through the processes of

yulyashka [42]

Answer: The standard state refers to 1 atm and $25^{o}C$ .

Explanation:

It is known that a chemical/substance can either be present in a solid, liquid or gaseous state.

So, when the phase of a substance like solid, liquid or gas is present at 1 atmosphere pressure and at a temperature of $25^{o}C$ then it known as standard state of substance.

Thus, we can conclude that standard state refers to 1 atm and $25^{o}C$ .

4 0

2 years ago

In the bromination of arenes, which of the following statements regarding the reaction is true?a.The hydrocarbon is used in exce

Olenka [21]

The hydrocarbon is used in excess.

<h3><u>Explanation</u>:</h3>

The bromination of an arene is not simple as bromination of an alkane. This is because the carbocation or free radicle formation in benzene is a very energy consuming process. This is why a lewis base like aluminium bromide or ferric bromide is used. The ferric bromide takes in the bromine radicle and forms the brominium cation which helps in the formation of electrophile. Now this electrophile brominium cation attacks the benzene ring and forms a temporary sp3 hybrid carbon intermediate. Then the hydrogen is taken by the FeBr4- forming HBr and regenerating the FeBr3 as well as Aromaticity of the arene species at the same time. Here hydrocarbon is used in excess just to prevent the chances of multiple substitution in the same arene molecule.

8 0

3 years ago

What is oxidized in a galvanic cell with aluminum and gold electrodes ?

k0ka [10]

Answer:

Aluminum metal

Explanation:

In order to properly answer this or a similar question, we need to know some basic rules about galvanic cells and standard reduction potentials.

First of all, your strategy would be to find a trusted source or the table of standard reduction potentials. You would then need to find the half-equations for aluminum and gold reduction:

$Al^{3+}+3e^-\rightarrow Al; E^o=-1.66 V$

$Au^{3+}+3e^-\rightarrow Au; E^o=1.50 V$

Since we have a galvanic cell, the overall reaction is spontaneous. A spontaneous reaction indicates that the overall cell potential should be positive.

Since one half-equation should be an oxidation reaction (oxidation is loss of electrons) and one should be a reduction reaction (reduction is gain of electrons), one of these should be reversed.

Thinking simply, if the overall cell potential would be obtained by adding the two potentials, in order to acquite a positive number in the sum of potentials, we may only reverse the half-equation of aluminum (this would change the sign of E to positive): $Al\rightarrow Al^{3+}+3e^-; E^o=1.66 V\\Au^{3+}+3e^-\rightarrow Au; E^o=1.50 V$

Notice that the overall cell potential upon summing is:

$E_{cell}=1.66 V + 1.50 V=3.16 V$

Meaning we obey the law of galvanic cells.

Since oxidation is loss of electrons, notice that the loss of electrons takes place in the half-equation of aluminum: solid aluminum electrode loses 3 electrons to become aluminum cation.

6 0

2 years ago

Describe Chemical and physical changes of ice water placed in the refrigerator

Talja [164]

So in a chemical change, the product would loses its properties, would form new products and would not be easily reversed.

In a physical change, the products WILL NOT lose any of their properties, WILL NOT form any new products and WILL be easily reversed.

Talking about Water turning to ice I would say it’s all about physical change and not chemical change.
But I would suggest you to either make a research about it or ask your teacher :))

6 0

2 years ago

What evidence did Mendeleev use to decide that the alkali metals should be in the same group?

natta225 [31]

Answer:

they all reacted the same

Explanation:

8 0

3 years ago