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3 years ago

Classify the four reactions that your group analyzed today as being either endothermic or exothermic

1 answer:

4 0

Chemical reactions are basically divided into two major classes depending on whether the reaction lose energy or gain energy from the environment during the course of the reaction. The two classes of reaction are exothermic and endothermic reaction.
An exothermic reaction is a type of reaction in which the reaction system lose energy to the environment and thus, the energy content of the reactants is more than that of the product formed. Because of this, the enthapyl change of an exothermic reaction is always negative.
An endothermic reaction is a type of reaction in which the reaction system absorb energy from the environment. Thus, the energy contents of the products is always higher than that of the reactants and the enthapyl change of the reaction is always positive. During the course of the reaction, the reaction container is usually cold to the touch because energy is been absorbed from the environment.

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How does the hydrosphere lithosphere atmosphere and biosphere work

umka21 [38]

They are all layers of the atmosphere that exist as separate layers but cooperate with each other. The hydrpsphere is the water part of the atmosphere such as oceans, sea, and lake's. The lithosphere is the under earth action that is happening where such things as faults, and volcanoes occur. The biosphere is where all life exist such as me, you, and animals.

4 0

3 years ago

Does anyone know how to write out the formula for these?? not just the answer x

Tju [1.3M]

Idk how to write the formula I had this same question

5 0

3 years ago

If 75 grams of oxygen react, how many grams of aluminum are required?

german

Answer:

84.24 g

Explanation:

Given data:

Mass of oxygen = 75 g

Mass of Al required to react = ?

Solution:

Chemical equation:

4Al + 3O₂ → 2Al₂O₃

Number of moles of oxygen:

Number of moles = mass/ molar mass

Number of moles = 75 g/ 32 g/mol

Number of moles = 2.34 mol

Now we will compare the moles of oxygen with Al.

O₂ : Al

3 : 4

2.34 : 4/3×2.34 = 3.12 mol

Mass of Al required:

Mass = number of moles × molar mass

Mass = 3.12 mol × 27 g/mol

Mass = 84.24 g

5 0

3 years ago

Consider this reaction:

Brilliant_brown [7]

Answer : The oxidation state of Mg in Mg(s) is (0).

Explanation :

Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.

Oxidation numbers are generally written with the sign (+) and (-) first and then the magnitude.

Rules for Oxidation Numbers are :

The oxidation number of a free element is always zero.

The oxidation number of a monatomic ion equals the charge of the ion.

The oxidation number of Hydrogen (H) is +1, but it is -1 in when combined with less electronegative elements.

The oxidation number of oxygen (O) in compounds is usually -2.

The oxidation number of a Group 17 element in a binary compound is -1.

The sum of the oxidation numbers of all of the atoms in a neutral compound is zero.

The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.

The given chemical reaction is:

$Mg(s)+2H_2O(l)\rightarrow Mg(OH)_2(s)+H_2(g)$

In the given reaction, the oxidation state of Mg in Mg(s) is (0) because it is a free element and the oxidation state of Mg in $Mg(OH)_2$ is (+2).

Hence, the oxidation state of Mg in Mg(s) is (0).

3 0

3 years ago

Zainab is in science class, and he is studying an organism that reproduces sexually. The genetic material of the organism

Tanzania [10]

Answer:

The genetic material of the organism will be DNA.

Explanation:

Sexual reproduction can be described as a type of reproduction in which offsprings with genetic diversity are produced. Sexual reproduction occurs by the process of meiosis.

DNA is the genetic material which is passed from the parents to the offsprings at the time of fertilization. However, the phenomenon of individual assortment and crossing over during the process of meiosis produces genetic variability among the children and the parents.

8 0

3 years ago

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