Ask question

Ask question

All categories

2 years ago

8

Online class this is my TEACHER

1 answer:

Karolina [17]2 years ago

3 0

Answer:

he kinda looks like a tall kid in a suit

You might be interested in

What happens to light when it is captured by a material?<br> plz, help meeeee!!!!! TwT

Nat2105 [25]

During absorption, frequency of the incoming light wave is either near or at the energy level of the electrons in the matter of the material. The electrons will absorb the energy of the light wave and change their energy state.

Hope that helps! :)

3 0

2 years ago

Please am confused and need help

alex41 [277]

Answer:

1. C

2. C

3. A

4. C

5. True

6. C

Explanation:

1. C The answer is conduction because the heat was transferred through direct contact.

2. C The answer convection because the heat was transferred through a medium (liquid/gas).

3. A The answer is conduction because the heat was transferred through direct contact.

4. C The answer is radiation because the heat was transferred through thermal emission.

5. True. This is because the air that is warmed rises, causing the cool air to replace it. You can picture it like the scenario in question 2.

6. C

3 0

3 years ago

What is the empirical formula of a compound that contains 43.38% sodium, 11.33% carbon, and 45.29% oxygen?

Vlad1618 [11]

What is the empirical formula of a compound that contains 43.38% sodium, 11.33% carbon, and 45.29% oxygen?

Na2CO3

6 0

2 years ago

Read 2 more answers

The insulating and packing material Styrofoam is a dating and packing material Styrofoam is a polymer of styrene. Find the molec

Nataly [62]

Explanation:

In order to find the molecular formula, we have to find the empirical formula first of all.

It is known that is a styrofoam, elements present are carbon and hydrogen atoms.

Element % Atomic mass Molar ratio Simple ratio

C 92.25 12.01 $\frac{92.25}{12.01}$ = 7.68 $\frac{7.68}{7.68}$ = 1

H 7.75 1.008 $\frac{7.75}{1.008}$ = 7.68 $\frac{7.68}{7.68}$ = 1

As empirical formula of styrofoam is C_{x}H_{x}.

Hence, empirical mass = (12.01 + 1.008) g/mol = 13.018 g/mol = 13.0 g/mol (approx)

Molar mass given is 104 g/mol.

So, $\frac{\text{molar mass}}{\text{empirical formula mass}}$ = $\frac{104}{13.0}$ = 8

Thus, we can conclude that molecular formula of the given styrene is $C_{8}H_{8}$ .

8 0

3 years ago

A sheet of polyethylene 1.5-mm thick is being used as an oxygen barrier at a temperature of 600K. If the flux is 2.48 x 10-5 kg/

Eddi Din [679]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The concentration of high-pressure side is $C_1 = 0.722 \ kg/m^3$

Explanation:

From the question we are told that

The thickness of the polyethylene is $d = 1.5 \ mm = 0.0015 \ m$

The temperature is $T = 600 \ K$

The flux is $JA = 2.48 *10^{-5} \ kg/m^2\cdot s$

The concentration on the low-pressure side is $C_2 = 0.5 \ kg/m^3$

The initial diffusivity is $D_o = 6.2 *10^{-4} \ m^2 /s$

The activation energy for diffusion is $Q_d = 41 \ kJ /mol = 41*10^3 J /mol$

Generally the diffusivity of the oxygen at 600 K can be mathematically evaluated as

$D = D_o * e^{- \frac{Q_d}{R * T } }$

substituting values

$D = 6.2*10^{-4} * e^{- \frac{41 *10^3}{8.314 * 600 } }$

$D = 1.671 *10^{-7} \ m^2 /s$

Generally the flux is mathematically represented as

$JA = D * \frac{C_1 -C_2}{d}$

Where $C_1$ is the concentration of oxygen at the higher side

So

$C_1 = d * \frac{JA}{D} + C_2$

substituting values

$C_1 = 0.0015 * \frac{2.48*10^{-5}}{1.671*10^{-7}} + 0.5$

$C_1 = 0.722 \ kg/m^3$

6 0

3 years ago