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enot [183]
4 years ago
5

Which of the following is a sign a chemical reaction has occurred?

Chemistry
2 answers:
tankabanditka [31]4 years ago
6 0
A solid dissolves in abolishing forms from the mixing of 2 liquids
dimulka [17.4K]4 years ago
6 0

Answer: A solid forms when two liquids are mixed.

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.

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.

1. A solid dissolves in liquid: Only the phase of the solid changes to aqueous and no new substance is formed, thus is a physical change.

2. A solid forms when two liquids are mixed: two liquids can forma  solid only on chemical combination and formation of new substance.

3. A solid melts to a liquid when it is heated: Only the phase of the solid changes to liquid, no new substance is formed, thus is a physical change.

4. A solid metal changes shape: Only the shape of the solid changes, thus is a physical change.

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Given the following reaction and data, A + B → Products
natima [27]

Answer:

a. Rate = k×[A]

b. k = 0.213s⁻¹

Explanation:

a. When you are studying the kinetics of a reaction such as:

A + B → Products.

General rate law must be like:

Rate = k×[A]ᵃ[B]ᵇ

You must make experiments change initial concentrations of A and B trying to find k, a and b parameters.

If you see experiments 1 and 3, concentration of A is doubled and the Rate of the reaction is doubled to. That means a = 1

Rate = k×[A]¹[B]ᵇ

In experiment 1 and to the concentration of B change from 1.50M to 2.50M but rate maintains the same. That is only possible if b = 0. (The kinetics of the reaction is indepent to [B]

Rate = k×[A][B]⁰

<h3>Rate = k×[A]</h3>

b. Replacing with values of experiment 1 (You can do the same with experiment 3 obtaining the same) k is:

Rate = k×[A]

0.320M/s = k×[1.50M]

<h3>k = 0.213s⁻¹</h3>

6 0
3 years ago
When a small amount of 12 M HNO3(aq) is added to a buffer solution made by mixing CH3NH2(aq) and CH3NH3Cl(aq) , the pH of the bu
fredd [130]

Answer:

a. CH3NH2(aq) + H⁺ → CH3NH3⁺

Explanation:

The mixture of a weak base as CH3NH2 with its conjugate acid CH3NH3Cl produce a buffer. As the weak acid is in equilibrium with water, the mixture of the weak base and its conjugate base produce that the acid or base released react avoiding the change in pH.

For example, when a strong acid as HNO3 reacts, the weak base will react producing the conjugate base, that is:

CH3NH2(aq) + H⁺ → CH3NH3⁺

Right answer is:

<h3>a. CH3NH2(aq) + H⁺ → CH3NH3⁺</h3>

5 0
3 years ago
1. Which of the following parts allow different activities of the cell to happen? A cytoplasm C vacuole B. lysosome D. vesicle 2
Anna35 [415]

Answer: A. Cytoplasm

Explanation: Cytoplasm is a jelly, like material that fills up the remaining space in the cell. It is also responsible in making the shape of the cell. Without it, other parts of the cells or the organelles cannot make its function because it serves as the hallway of the transportation of the nutrients needed by each cell.

Learn more: https://brainly.ph/question/73078

4 0
2 years ago
which of the following structures are tubes? A. Eustachian, Pharynx, Bronchi. B. Cilia, Adenoids, mucous, epiglottis. C. Apex, M
Arte-miy333 [17]
The correct answer among the choices given is option A. Eustachian, Pharynx, Bronchi are structures that ensembles a tube. The Eustachian tube is a narrow passage from the pharynx to the middle ear. Pharynx is a passageway leading from the oral and nasal cavities to the larynx and the esophagus. Lastly, bronchi is an airway in the respiratory tract.
6 0
3 years ago
You find small pieces of ice instead of ice cubes in the freezer. State how this is possible.
Nat2105 [25]
Well, if u had a spilled liquid in there (we'll simply go with water) and you had the freezer at a cold temperature it would change (like,icycles on trees when it's snowing)
4 0
3 years ago
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