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Akimi4 [234]
4 years ago
9

The volume of water in a beaker was 315 mL. After 7 days, the volume of the water was 300 mL. Kayla says that a chemical change

occurred, but Maria says it was a physical change. Who is correct?
A. Maria is right. The water in the beaker changed from a liquid to a gas when it evaporated. Changing states of matter is a physical change.


B. Neither Kayla nor Maria are correct since the water just evaporated. No change took place.


C. Kayla is right. The water changed from a water to a gas. A gas is a new and different substance. This is a chemical change.


D. Both Kayla and Maria are correct. The water changed states which is a physical change, but it also changed into a new substance which is a chemical change.
(I think that it could be A or B, but idk.)
Chemistry
2 answers:
Nuetrik [128]4 years ago
7 0

Answer: A. Maria is right. The water in the beaker changed from a liquid to a gas when it evaporated. Changing states of matter is a physical change.

Explanation: A physical reaction is defined as the reaction in which a change in shape, size takes place. No new substance gets formed in these reactions as no rearrangement of atoms take place.

A chemical reaction is defined as the reaction in which a change in chemical composition takes place. A new substance is formed in these reactions as rearrangement of atoms take place.

Evaporation of water is a physical change as only state of the water changes from liquid to gas and no new substance gets formed.Thus Maria is right.

Monica [59]4 years ago
3 0

Answer is "A".

Explanation;

Physical changes mean an arrangement of particles of a given substance without producing new substance but changes in physical form of the substance.

<em>Example :</em> vaporization of water ( water goes its gaseous phase from liquid form).

Chemical changes mean an arrangement of particles while forming new substance.

<em>Example : </em>heating of CaCO₃. (In this process CaO and CO₂ are formed).

In this problem, the volume of water has decreased. Hence, it can be said that this is an example of physical changes due to not forming of new substance.

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4 0
3 years ago
Predict which member of each pair will be more acidic. Explain your answers. (a) methanol or tert-butyl alcohol (b) 2-chloroprop
Art [367]

Answer:

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B. 2-chloropropan-1-ol

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D. 2,2-difluoropropan-1-ol

Explanation:

Primary alcohols are stronger acids than secondary alcohols which are stronger than tertiary alcohols.

This trend is so because of the stability of the alkoxide ion formed(stabilising the base, increases the acidity). A more stabilised alkoxide ion is a weaker conjugate base (dissociation of an acid in water).

By electronic factors, When there are alkyl groups donating electrons, the density of electrons on th O- will increase a d thereby make it less stable.

By stearic factors, More alkyl group bonded to the -OH would mean the bulkier the alkoxide ion which would be harder to stabilise.

Down the group of the periodic table, basicity (metallic character) decreases as we go from F– to Cl– to Br– to I– because that negative charge is being spread out over a larger volume that is electronegativity decreases down the group.

Electronegative atoms give rise to inductive effect and a decrease in indutive effects leads to a decrease in acidity. Therefore an Increasing distance from the -OH group lsads to a decrease in acidity.

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A. Methanol

B. 2-chloropropan-1-ol

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D. 2,2-difluoropropan-1-ol

6 0
4 years ago
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a.solution

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Answer:

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Answer:

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However, when a gaseous solute is dissolved in a liquid; as the temperature is increased and solvent molecules are able to collide more frequently with the solute molecules and dislodge them, gas molecules dissolved in the liquid are more likely to escape to the gas phase and not return due to the increase in their kinetic energy.

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