Which statement is true of a food web?

A 2.0-liter aqueous solution contains a total of 3.0 moles of dissolved NH4Cl at 25°C and standard pressure.

vladimir1956 [14]

The molarity is a concentration unit which defined as the number of moles of solute divided by the number of liters of solution. So the molarity of the solution is 3/2=1.5 mol/L.

7 0

2 years ago

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In what type of climate do trees produce narrower rings?

poizon [28]

Answer:

cool and dry

8 0

2 years ago

In models of molecules, spheres of different colors and

AlladinOne [14]

Answer:

D

Explanation:

According to this question, each model of molecules in the options contains spheres of different colors and sizes representing different types of atoms. The atoms of the same element are the spheres of same color and size while atoms of different element are of different color or size.

Therefore, the model showing a molecule of a substance that is made up of three elements is model D because it is made up of three distinct spheres representing atoms of each element.

- The red sphere is the atom of the first element

- The big dark sphere is the atom of the second element

- The small white sphere is the atom of the third element

3 0

3 years ago

Write a balanced overall reaction from these unbalanced half-reactions sn and ag

loris [4]

Balance each one by adding electrons to make the charges on both sides the same:

Sn--> Sn2+ + 2 e-
Ag+ + 1 e- --> Ag

Now, you have to have the same number of electrons in the two half-reactions, so multiply the second one by 2 to get:

2 Ag+ + 2 e- --> 2 Ag

Now, just add the two half reactions together, cancelling anything that's the same on both sides:

2 Ag+ + Sn --> Sn2+ + 2 Ag

And you're done.

8 0

3 years ago

How are the following aspects of a reaction affected by the addition of a catalyst? 1) activation energy of the reverse reaction

snow_tiger [21]

These are four questions and four answers.

Answers:

1) activation energy of the reverse reaction

b. Decreased

2) Rate of the forward reaction

a. Increased

3) Rate of the reverse reaction

a. Increased

4) Activation energy of the forward reaction

b. decreased

Explanation:

Activarion energy is the energy required by the reactants to form the intermediate transition state and become products.

Catalysts are substances that change the path of the chemical reactions, lowering the activation energy, and thus speeding up the rate of the reactions, since the products can reach the new lower activation energy faster.

The equilibrium reactions are the chemical process in which two reactions, the forward and the reverese reactions, occur simultaneously and at the same rate. The equlibrium reactions may be represented by:

A ⇄ B

Where A → B is the direct or forward reaction, and A ← B is the reverse reaction (note the inversed arrow, from right to left).

For the direct reaction A represents the reactants and B represents the products. On the other hand, B represents the reactants and A represents the reactants of the reverse reaction and A. This, is A is the reactant of the forward reaction and the product of the reverse reaction, while B is the reactant of the reverse reaction and the product of the forward reaction.

Since, the addition of a catalyst lowers the activation energy of the process, the new activation energy is lower for both the forward and the reverse reaction, meaning that:

1. The activation energy of the reverse reaction is decreased (option b. of the first question)

2. The rate of the forward reaction is increased (option a. of the second question)

3. The rate of the reverse reaction is increased (option a. of the third question).

4. Activation energy of the forward reaction is decreased (option b. of the fourth question).

In summary, the addition of a catalyst decreases the activation energy for both forward and reverse reactions, and increases the rate of both forward and reverse reactions.

3 0

3 years ago

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