Which of the following is required to change the state of matter?

How many of the following are oxidation-reduction reactions? I. reaction of a metal with a nonmetal II. synthesis III. combustio

nadezda [96]

Answer : The oxidation-reduction reactions are:

I. reaction of a metal with a nonmetal

II. synthesis

III. combustion

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

I. Reaction of a metal with a nonmetal :

When sodium react with chlorine gas then it react to give sodium chloride.

$2Na+Cl_2\rightarrow 2NaCl$

In this reaction, the oxidation state of sodium changes from (0) to (+1) and shows oxidation and the oxidation state of chlorine changes from (0) to (-1) and shows reduction. So, It is an oxidation-reduction reaction.

II. Synthesis reaction :

A chemical reaction where multiple substances or reactants combine to form a single product.

When hydrogen react with oxygen then it react to give water.

$2H_2+O_2\rightarrow 2H_2O$

In this reaction, the oxidation state of hydrogen changes from (0) to (+1) and shows oxidation and the oxidation state of oxygen changes from (0) to (-2) and shows reduction. So, It is an oxidation-reduction reaction.

III. Combustion reaction :

A chemical reaction in which a hydrocarbon reaction with the oxygen to give product as carbon dioxide and water.

When methane react with oxygen gas then it react to give carbon dioxide and water.

$CH_4+2O_2\rightarrow CO_2+2H_2O$

In this reaction, the carbon of methane gain oxygen and shows oxidation and the oxygen gas gain hydrogen and shows reduction. So, It is an oxidation-reduction reaction.

IV. Precipitation reaction :

It is defined as the reaction in which an insoluble salt formed when two aqueous solutions are combined.

The insoluble salt that settle down in the solution is known an precipitate.

It is a double displacement reaction. So, it is not an oxidation-reduction reaction.

V. Decomposition reaction :

A chemical reaction in which the the larger molecule decomposes to give two or more smaller molecules.

The oxidation state remains same on reactant and product side. So, it is not an oxidation-reduction reaction.

3 0

3 years ago

What type of reaction does each of the following equations represent?

vekshin1

Answer:

Option C. Decomposition

Explanation:

To know which option is correct, it is important we know what is a single displacement reaction, double displacement reaction and decomposition reaction.

A Single displacement reaction can be defined as a reaction in which a single element is replaced by another element in a compound.

A double displacement reaction is a reaction involving the exchange of ions of two parts of ionic compounds to form two different compounds.

A decomposition reaction is a reaction in which a compound splits into two or more simpler compound or element.

Bearing the above definitions in mind and considering the question given above, we can conclude that the reaction given in the question above is a decomposition reaction since the compound (NH₄OH) splits into two different compound (NH₃ and H₂O)

3 0

3 years ago

Tamoxifen is a drug used to prevent recurrence of certain types of breast cancers that require estrogen to grow. Tamoxifen binds

fredd [130]

Answer:

Tamoxifen is an irreversible, competitive inhibitor.

Explanation:

In order to binds to the active site of the estrogen receptor protein, tamoxifen have to compete with the other chemical compound, and inhibits the estrogen release, so it is a competitive inhibitor. Then, you said that when tamoxifen binds to the receptor, the protein is permanently deactivated, so it is also irreversible.

8 0

3 years ago

describe the general trend in electronegativity as metals in group 2 on the periodic table are concidered in order of increasing

hjlf

Answer:

Electronegativity decrease in group from top to bottom

Explanation:

6 0

3 years ago

Carbon dioxide and helium which has a higher van der waals force of attraction between molecules

raketka [301]

Answer:

Carbon dioxide

Explanation:

Neither helium nor carbon dioxide has a molecular dipole, so their strongest van der Waals attractive forces are London forces.

Helium is a small spherical atom with only a two electrons, so its atoms have quite weak attractions to each other.

CO₂ is a large linear molecule. It has more electrons than helium, so the attractive forces are greater. Furthermore, the molecules can align themselves compactly side-by-side and maximize the attractions (see below).

For example. CO₂ becomes a solid at -78 °C, but helium must be cooled to -272 °C to make it freeze (that's just 1 °C above absolute zero).

7 0

3 years ago