What is the address of elements?

describe how to put a food you enjoy such as hamburger pizza or muffin identify one physical change that takes place as this foo

Debora [2.8K]

One chemical change would be baking the muffin.
One physical change would be chopping the fruits to add to the mixture

7 0

3 years ago

What is the mass % of iron in Fe(CH3CO2)2<br><br> (Fe=iron=55.85)

Serjik [45]

The mass percentage is 15.1465%.

5 0

4 years ago

¿Qué tipo de Inter conversión existe en una celda galvánica o en una celda electrolítica? a) de energía química a energía eléctr

insens350 [35]

Answer:

Opción a)

Explanation:

En este caso, vamos a explicartelo descartando opciones. Para empezar el proceso que existe en una celda galvánica o electrolítica, es lo que uno llama un proceso de Electroquímica, y permite manipular y usar la energía electrica para generar una reacción.

En este caso, yo tengo por ejemplo una celda galvánica con dos componentes como hierro y cobre conectados mediante una celda. El proceso de reacción entre ellos es lo que ayudará a que se genere energia electrica y esto, encendería un bombillo de luz. También puede ocurrir lo contrario. Con electricidad, se genera una reacción química. En estos casos, se genera una reacción de tipo REDOX (Oxido reducción).

Tomando en cuenta esto, la respuesta correcta sería la opción a). Veamos por que las otras opciones no son:

b) Energía eléctrica a química

Esta opción es falsa, porque estaría supeditando que una reacción solo puede darse por medio de una manipulación de la energía electrica y en las celdas galvánicas no ocurre eso, sino al revés.

c) Energía química a eléctrica

Falsa, porque es igual que la anterior, solo está supeditado a que ocurra este tipo de reacciones y no es así.

d) energía lumínica a eléctrica

Falso porque la energía lumínica proviene tambien de la electricidad, y en el caso de una celda galvánica se genera una reacción por lo que existe otro tipo de energía.

Espero esto te ayude.

7 0

3 years ago

A mysterious white powder could be powdered sugar (C12H22O11), cocaine (C17H21NO4), codeine (C18H21NO3), norfenefrine (C8H11NO2)

rodikova [14]

Norfenefrine (C₈H₁₁NO₂).

<h3>Further explanation</h3>

We will solve a case related to one of the colligative properties, namely freezing point depression.

The freezing point of the solution is the temperature at which the solution begins to freeze. The difference between the freezing point of the solvent and the freezing point of the solution is called freezing point depression.

$\boxed{ \ \Delta T_f = T_f(solvent) - T_f(solution) \ } \rightarrow \boxed{ \ \Delta T_f = K_f \times molality \ }$

<u>Given:</u>

A mysterious white powder could be,

powdered sugar (C₁₂H₂₂O₁₁) with a molar mass of 342.30 g/moles,
cocaine (C₁₇H₂₁NO₄) with a molar mass of 303.35 g/moles,
codeine (C₁₈H₂₁NO₃) with a molar mass of 299.36 g/moles,
norfenefrine (C₈H₁₁NO₂) with a molar mass of 153.18 g/moles, or
fructose (C₆H₁₂O₆) with a molar mass of 180.16 g/moles.

When 82 mg of the powder is dissolved in 1.50 mL of ethanol (density = 0.789 g/cm³, normal freezing point −114.6°C, Kf = 1.99°C/m), the freezing point is lowered to −115.5°C.

<u>Question: </u>What is the identity of the white powder?

<u>The Process:</u>

Let us identify the solute, the solvent, initial, and final temperatures.

The solute = the powder
The solvent = ethanol
The freezing point of the solvent = −114.6°C
The freezing point of the solution = −115.5°C

Prepare masses of solutes and solvents.

Mass of solute = 82 mg = 0.082 g
Mass of solvent = density x volume, i.e., $\boxed{ \ 0.789 \ \frac{g}{cm^3} \times 1.50 \ cm^3 = 1.1835 \ g = 0.00118 \ kg \ }$

We must prepare the solvent mass unit in kg because the unit of molality is the mole of the solute divided by the mass of the solvent in kg.

The molality formula is as follows:

$\boxed{ \ m = \frac{moles \ of \ solute}{kg \ of \ solvent} \ } \rightarrow \boxed{ \ m = \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }$

Now we combine it with the formula of freezing point depression.

$\boxed{ \ \Delta T_f = K_f \times \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }$

It is clear that we will determine the molar mass of the solute (denoted by Mr).

We enter all data into the formula.

$\boxed{ \ -114.6^0C - (-115.5^0C) = 1.99 \frac{^0C}{m} \times \frac{0.082 \ g}{Mr \times 0.00118 \ kg} \ }$

$\boxed{ \ 0.9 = \frac{1.99 \times 0.082}{Mr \times 0.00118} \ }$

$\boxed{ \ Mr = \frac{0.16318}{0.9 \times 0.00118} \ }$

We get $\boxed{ \ Mr = 153.65 \ }$

These results are very close to the molar mass of norfenefrine which is 153.18 g/mol. Thus the white powder is norfenefrine.

<h3>Learn more</h3>

The molality and mole fraction of water brainly.com/question/10861444
About the mass and density of ethylene glycol as an antifreeze brainly.com/question/4053884
About the solution as a homogeneous mixture brainly.com/question/637791

Keywords: a mysterious white powder, sugar, cocaine, codeine, norfenefrine, fructose, the solute, the solvent, dissolved, ethanol, normal freezing point, the freezing point depression, the identity

7 0

3 years ago

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Which of these is the best evidence that a chemical reactions occurs when coal burns?

laila [671]

Answer:

It’s b even check quizzes

Explanation:

3 0

3 years ago

Read 2 more answers