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2 years ago

Cuál es la importancia de una fórmula química y explique las clases de fórmulas con sus ejemplos respectivos.

Chemistry

1 answer:

Ksenya-84 [330]2 years ago

8 0

Answer and Explanation:

Las fórmulas químicas sirven para conocer qué elementos químicos y en qué cantidad están presentes en un compuesto químico. Por ejemplo: la fórmula química del dióxido de carbono es CO₂. Esta fórmula nos indica que la molécula de dióxido de carbono está formada por 1 átomo del elemento químico carbono y 2 átomos del elemento oxígeno.

Los diferentes tipos de fórmulas químicas son: fórmula empírica, fórmula molecular, fórmula semi-desarrollada y fórmula desarrollada. Tomando como ejemplo al compuesto <em>butano</em>:

- Fórmula empírica: C₂H₅ (indica que hay 2 átomos de C por cada 5 átomos de H; es una fórmula mínima)

- Fórmula molecular: C₄H₁₀ (indica que en realidad cada molécula de butano tiene 4 átomos de C y 10 átomos de H).

- Fórmula semi-desarrollada: CH₃CH₂CH₂CH₃ (indica el órden en que se unen los átomos en la molécula).

-Fórmula desarrollada: ver dibujo adjunto (indica cómo están unidos los átomos dentro de la molécula. Ahora vemos los enlaces entre los átomos y que los 2 átomos de C de los extremos están unidos a 3 átomos de H y a otro C, y los dos átomos de C del medio están unidos cada uno a 2 C y 2 H).

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How much heat is needed to boil 3,000 mL of water at its boiling point, 100 C?

Karo-lina-s [1.5K]

Answer: 100C of heat is needed.

Explanation: That is the heating point of water

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3 years ago

1. For each of the molecules below, determine the electron geometry, molecule geometry, and bond

Alexxx [7]

Answer:

CCl4- tetrahedral bond angle 109°

PF3 - trigonal pyramidal bond angles less than 109°

OF2- Bent with bond angle much less than 109°

I3 - linear with bond angles = 180°

A molecule with two double bonds and no lone pairs - linear molecule with bond angle =180°

Explanation:

Valence shell electron-pair repulsion theory (VSEPR theory) helps us to predict the molecular shape, including bond angles around a central atom, of a molecule by examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement which tends to minimize repulsions between these electron pairs by maximizing the distance between them. The electrons in the valence shell of a central atom are either bonding pairs of electrons, located primarily between bonded atoms, or lone pairs. The electrostatic repulsion of these electrons is reduced when the various regions of high electron density assume positions as far apart from each other as possible.

Lone pairs and multiple bonds are known to cause more repulsion than single bonds and bond pairs. Hence the presence of lone pairs or multiple bonds tend to distort the molecular geometry geometry away from that predicted on the basis of VSEPR theory. For instance CCl4 is tetrahedral with no lone pair and four regions of electron density around the central atom. This is the expected geometry. However OF2 also has four regions of electron density but has a bent structure. The molecule has four regions of electron density but two of them are lone pairs causing more repulsion. Hence the observed bond angle is less than 109°.

8 0

2 years ago

Complete and balance the following redox equation using the set of smallest whole– number coefficients. Now sum the coefficients

Elena L [17]

Answer : The balanced chemical equation in a acidic solution is,

$BrO_3^-(aq)+6H^+(aq)+3Sb^{3+}(aq)\rightarrow Br^-(aq)+3H_2O(l)+3Sb^{5+}(aq)$

The sum of the coefficients is, 17

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

Rules for the balanced chemical equation in acidic solution are :

First we have to write into the two half-reactions.

Now balance the main atoms in the reaction.

Now balance the hydrogen and oxygen atoms on both the sides of the reaction.

If the oxygen atoms are not balanced on both the sides then adding water molecules at that side where the less number of oxygen are present.

If the hydrogen atoms are not balanced on both the sides then adding hydrogen ion $(H^+)$ at that side where the less number of hydrogen are present.

Now balance the charge.

The given chemical reaction is,

$BrO_3^-(aq)+Sb^{3+}(aq)\rightarrow Br^-(aq)+Sb^{5+}(aq)$

The oxidation-reduction half reaction will be :

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-$

First balance the main element in the reaction.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-$

Now balance oxygen atom on both side.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-+3H_2O$

Now balance hydrogen atom on both side.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-+6H^+\rightarrow Br^-+3H_2O$

Now balance the charge.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}+2e^-$

Reduction : $BrO_3^-+6H^++6e^-\rightarrow Br^-+3H_2O$

The charges are not balanced. Now multiplying oxidation reaction by 3 and then adding both equation, we get the balanced redox reaction.

Oxidation : $3Sb^{3+}\rightarrow 3Sb^{5+}+6e^-$

Reduction : $BrO_3^-+6H^++6e^-\rightarrow Br^-+3H_2O$

The balanced chemical equation in acidic medium will be,

$BrO_3^-(aq)+6H^+(aq)+3Sb^{3+}(aq)\rightarrow Br^-(aq)+3H_2O(l)+3Sb^{5+}(aq)$

The sum of the coefficients = 1 + 6 + 3 + 1 + 3 + 3

The sum of the coefficients = 17

7 0

3 years ago

A tank of gas has partial pressures of nitrogen and oxygen equal to 1.61 Ã— 104 kPa and 4.34 Ã— 103 kPa , respectively.What is t

Alchen [17]

Answer:

$20.44\times 10^3 kPa$ is the total pressure of the tank.

Explanation:

Partial pressures of nitrogen = $p_{N_2}=1.61\times 10^4 kPa$

Partial pressure of oxygen = $p_{O_2}=4.34\times 10^3 kPa$

Total pressure of gases in the tank = P

Applying Dalton's law of partial pressures :

$P=p_{N_2}+p_{O_2}=1.61\times 10^4 kPa+4.34\times 10^3 kPa$

$P=20.44\times 10^3 kPa$

$20.44\times 10^3 kPa$ is the total pressure of the tank.

7 0

2 years ago

Does ionic or covalent form solid crystals?

Alekssandra [29.7K]

Answer:

I hope it help

your welcome

5 0

2 years ago