please help me thank u !​

Answer:

0.175mol

Explanation:

Mole of a substance can be calculated using the formula as follows:

number of moles (n) = mass (m) ÷ molar mass (MM)

According to this question, there are 4.2g of Magnesium (Mg).

Molar mass of Magnesium = 24g/mol, hence, the number of moles of 4.2g of Mg is as follows:

n = 4.2g ÷ 24g/mol

n = 0.175mol

Answer:

dont know, will let uk in 2 mins

Explanation:

Explanation:

hope this helps you to understand:)

Answer:

0.0013 moles

Explanation:

moles = volume/ molar volume of gas

=240/24000cm3 (convert dm3 to cm3)

=0.0013

Answer:

—COOH

Explanation:

—COOH, acid group, containing 3 elements, C, carbon, O, oxygen, and H, hydrogen.

Answer:

20.25 W

Explanation:

Applying,

P = I²R.................... Equation 1

Where P = Power, I = current drawn by the test light, R = Resistance of the test light

From the question,

Given: I = 1.5 A, R = 9.00 Ω

Substitute these values into equation 1

P = (1.5²)(9)

P = 2.25×9

P = 20.25 W

Explanation:

Weight loss and weight maintenance.

Muscle gain.

Improved mood.

Improved heart health.

Answer:

a

Explanation:

It's a duh

Answer:

A. 31.0

Explanation:

Remember the formula [tex]Density = \frac{mass}{Volume}[/tex], or [tex]D=\frac{m}{V}[/tex].

The problem tells us that the density is 1.89 g/L, and that the volume is 16.4 L.(Remember that if the units are in some form of liters, it is volume, similar to how if the units are in grams, it is mass.)

Plug in the numbers for density and volume, and you will get:

[tex]1.89=\frac{m}{16.4}[/tex]

Then, multiply both sides by 16.4 to get:

m = 30.996 g ≈ 31.0 g

Hope this helps!

Answer:

Explanation:

The percentage error of a certain measurement can be found by using the formula

[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]

From the question

actual density = 7.80 g/cm³

error = 7.30 - 7.80 = 0.5

We have

[tex]p(\%) = \frac{0.5}{7.8} \times 100 \\ = 6.410256...[/tex]

We have the final answer as

Hope this helps you

Answer:

pure

Explanation:

because there no additional substance

Answer:

hope it help u !!!!

Explanation:

Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers

Answer:

816L adicionales para mantener la concentración

Explanation:

Cuánta agua debe adicionar el cuidador para que se mantenga la concentración del desinfectante?

El desinfectante, NaClO, idealmente debe estar en una concentración de:

35.8g / 1000L = 0.0358g/L

Como el velador agregó 65g de desinfectante, la cantidad de agua necesaria es:

65g * (1L / 0.0358g) = 1816L de agua son necesarios

Asumiendo que el velador agregó 1000L, el cuidador debe agregar:

1816L - 1000L =

Answer:

In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.

Answer:

En la mejora de la investigación y la medicina.

Explicación:

La aparición del microscopio ha permitido la creación de nuevas áreas de estudio, tanto en la mejora de la investigación como en la medicina. La invención del microscopio nos permite crecer y desarrollarnos en el campo de la investigación y el estudio. Con este microscopio, los científicos pudieron descubrir la estructura de la célula, así como las partículas subatómicas que están presentes dentro del átomo. Gracias a este microscopio, los científicos pudieron crecer y desarrollarse en el campo de la creación de nuevos medicamentos.

pH = 4

- log[H+]= 4

[tex][H+] = {e}^{ - 4} [/tex]

[tex][H+] = 54.6[/tex]

The pH of orange juice 4. The concentration of hydrogen of [tex]10^{-4}[/tex].

The pH scale, which originally stood for "potential of hydrogen," is being used to describe the acidity or alkalinity of aqueous solutions.

Calculation of concentration of hydrogen ion by using pH formula.

It can be calculated by using the formula.

pH = -log[[tex]H^{+}[/tex]].

[[tex]H^{+}[/tex]] = [tex]10^{-pH}[/tex]

[[tex]H^{+}[/tex]] = [tex]10^{-4}[/tex]

Therefore, the concentration of hydrogen ion  by using pH formula will be    [tex]10^{-4}[/tex].

To know more about pH

https://brainly.com/question/15289741

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Answer:

B) 0.211 M

Explanation:

Answer:

K = 2.96x10⁻¹⁰

Explanation:

Based on the initial reaction:

N2O4 ⇄ 2NO2; K = 1.5x10³

Using Hess's law, we can multiply this reaction changing K:

3 times this reaction:

3N2O4 ⇄ 6NO2; K = (1.5x10³)³ =3.375x10⁹

The inverse reaction has a K of:

6NO2 ⇄ 3N2O4 K = 1/3.375x10⁹;

potassium reacts the most vigorously.

The carbons on either side of the double bond are pointed in opposite directions.

Answer:

Boron B

Explanation:

According to the periodic table, Boron is the element with atomic mass of approximately 11 [i.e 10.81]

To calculate Neutrons

Neutrons = Mass number - Protons

Number of protons in Boron is same as atomic number which is 5

Thus, N = 11 - 5 = 6

Answer:

La respuesta está en la explicación

Explanation:

La viscosidad se puede definir como la resistencia al movimiento que presenta un líquido.

Al verter dos líquidos por separado en una pendiente, podrás ver cómo un líquido se tardará más en llegar al final de la pendiente que el otro. Este líquido será EL MÁS VISCOSO.

Así podrás, con el cronómetro, medir el tiempo que cada líquido se tarda en llegar a cierto punto de la pendiente, EL QUE TARDE MÁS SERÁ EL MÁS VISCOSO.

Answer:

im not entirely sure what needs to be done but the 2NH3 is the product and the other half is the reactants .

if any elements are added to others it is the reactants

this is a breakdown of a compound because the arrow always indicates the direction of the reaction .

Answer:

H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)

Explanation:

We must recall that the oxides of metals are bases. These metal oxides can react with dilute acids to yield salt and water.

Bearing that in mind, we want to obtain magnesium sulfate from a metal oxide and dilute acid.

In this case we need magnesium oxide and dilute sulphuric acid. The reaction occurs as follows;

H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)

Answer:

Because iodine is a liquid, it has no melting point. Iodine is not an electrical conductor because each molecule consists of two iodine atoms connected by a covalent bond that cannot be stimulated sufficiently to transmit electrical energy.

Explanation:

brainlist???

Explanation:

Because in an aqueous solution of iodine, iodine atoms are joined to each other by simple covalent bonds. Thus, when excitation occurs, the strength of the covalent bond is too weak to be able to transfer electrons, thus lacking the ability to conduct electricity.

Answer:

an epicenter is where an earthquake first hit

Answer:

The epicenter

Explanation:

The location below the earth's surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. ... These are smaller earthquakes that occur afterwards in the same place as the mainshock.

Answer:

on https://www.ck12.org/book/peoples-physics-concepts/section/20.1/

Explanation:

it shows for calcium 45 and maybe a possible equation on 3/4th's scroll down?