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2 years ago

Why might it be important in a real life situation, to know if a chemical or physical change occurred?

1 answer:

6 0

There are four signs that a chemical reaction has occurred: a change in color, a change in temperature, formation of a gas or formation of a precipitate. A precipitate is a solid that forms when two liquid solutions are mixed. As matter changes in a chemical reaction, it can either absorb or release energy.

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Which statement is a valid conclusion about the activation energy of the reverse reaction if the forward reaction is exothermic?

babunello [35]

Answer:

e) The activation energy of the reverse reaction is greater than that of the forward reaction.

Explanation:

Activation energy is the minimum amount of energy that is required by the reactants to start a reaction.
An exothermic reaction is a reaction that releases heat energy to the surrounding while an endothermic reactions is a reaction that absorbs heat from the surrounding.
In reversible reactions, when the forward reaction is exothermic it means the reverse reaction will be endothermic, therefore the reverse reaction will have a higher activation energy than the forward reaction. The activation energy of the reverse reaction will be the sum of the enthalpy and the activation energy of the forward reaction.

4 0

3 years ago

In the following equation:

Luda [366]

Answer:

FeCl₃

Explanation:

4FeCl₃ + 3O₂ => 2Fe₂O₃+ 6Cl₂

Given => 7moles 9moles

A simple way to determine which reagent is the limiting reactant is to convert all given data to moles then divide by the respective coefficients of the balanced equation. The smaller value will be the limiting reactant.

4FeCl₃ + 3O₂ => 2Fe₂O₃+ 6Cl₂

Given => 7/4 = 1.75* 9/3 = 3

*Smaller value => FeCl₃ is limiting reactant.

NOTE: However, when working problems, one must use original mole values given.

7 0

3 years ago

What power source uses the earths internal heat

nlexa [21]

Answer:

Geothermal power comes from Earth's internal heat

Explanation:

The description applied to power sources tends to match the names applied to the source of energy. Sometimes Latin, or other word derivations are used.

For example, "hydro-" refers to water, so it is no surprise that hydroelectric power comes from the movement of water. Of course, "nuclear" refers to the nuclei of the atoms that are split to release energy in a nuclear power plant. Similarly, "geo-" refers to Earth, and "thermal" refers to heat, so "geothermal" energy is the name given to energy derived from Earth's heat.

7 0

2 years ago

Question 1. In the following equation for the alpha decay of bismuth-214, supply the missing element that correctly completes th

Klio2033 [76]

Q1. TI (210/81Thallium)
Q2.
The answers are opposite from each other

7 0

2 years ago

Read 2 more answers

What is the molarity of a solution in which 250 grams of NaCl are dissolved in 2.9 L of water?

Maksim231197 [3]

Answer:

About 1.48 M.

Explanation:

The formula for molarity is mol/L.

So firstly, you must find the amount of moles in 250 grams of NaCl.

I do this by using stoichiometry. First, I find how nany grams are in a single mole of NaCl. This is around 58.44 grams/mole. Now that I know this, I can now use a stoich table. (250 g NaCl * 1 mol NaCl / 58.44 g NaCl). I plug this into my calculator.

I get that 250 grams of NaCl is equal to about 4.28 moles.

Now I just plug into the formula!

4.28 moles/2.9 L = about 1.48

I've attached a picture of my personal notes below which shows work I have done in similar equations.

3 0

1 year ago