Pls help tysm <3 :D:D

A 558 mg of a mixture of fluorene and benzoic acid was weighed out and subjected to an extraction and recrystallization. After t

kolbaska11 [484]

Answer:

See explanation

Explanation:

Mass of mixture of fluorene and benzoic acid = 558 mg

Mass of pure fluorene after purification = 185 mg of fluorene

Mass of pure benzoic acid after purification = 144 mg of benzoic acid

Percentage of fluorene int he mixture = 185mg/558mg * 100 = 33.15 %

Percentage of benzoic acid in the mixture = 144mg/558mg * 100 = 25.81 %

Percentage of impurities = 100% - [33.15 + 25.81]

Percentage of impurities = 100 - 58.96

Percentage of impurities = 41.04 %

4 0

3 years ago

Which is a balanced chemical equation? A. C7H16 + 5O2 6CO2 + 4H2O B. C7H16 + 11O2 7CO2 + 8H2O C. C7H16 + 14O2 7CO2 +5H2O D. C7H1

nadya68 [22]

Answer:

$\boxed{\text{B.}}$

Explanation:

B.

$\rm C$_7$H_{16}$ + 11O$_2$ $\longrightarrow \,$ 7CO$_2$ + 8H$_2$O$

BALANCED. 7C, 16H, and 22O on each side of equation.

A.

$\rm C$_7$H$_{16}$ + 5O$_2$ $\longrightarrow \,\rm 6CO$_2$ + 4H$_2$O$

NOT BALANCED. 7C on left and 6C on right.

C.

$\rm C$_7$H$_{16}$ + 14O$_2$ $\longrightarrow \,$ 7CO$_2$ + 5H$_2$O$

NOT BALANCED. 16H on left and 10H on right.

D.

$\rm C$_7$H$_{16}$ + 22O$_2$ $\longrightarrow \, $ 14CO$_2$ + 16H$_2$O$

NOT BALANCED. 7C on left and 14C on right.

3 0

3 years ago

PLZZZ HELP!!! A chemist has synthesized a heavy element in the laboratory and found that it had this electron configuration:

Hitman42 [59]

Answer:

Darmstadtium! Happy to help! :)

5 0

3 years ago

A. Match the term with its definition. (1 point)

Assoli18 [71]

Taking into account the definition of wavelength, frecuency and propagation speed:

Frequency: The number of waves passing a point in 1 second.
Wavelength: The distance between two adjacent wave peaks.
Velocity: The direction and speed at which a wave is traveling.

The equation that illustrates the relationship between wave velocity, frequency, and wavelength is v = f×λ.

<h3>Wavelength</h3>

Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).

<h3>Frequency</h3>

On the other side, frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

<h3>Propagation speed or velocity</h3>

Finally, the propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave disturbance propagates along its displacement.

The propagation speed relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:

v = f×λ

All electromagnetic waves propagate in a vacuum at a constant speed of 2,998 x 10⁸ m / s, the speed of light.

Therefore, the previous expression establishes an inversely proportional relationship between the frequency and the wavelength: The higher the frequency, the lower the wavelength and when the frequency is lower, the greater the wavelength.

<h3>Summary</h3>

In summary, the definition of frequency, wavelength and velocity are: