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3 years ago

What causes the appearance of lines in an emission spectrum?

Chemistry

1 answer:

Nikitich [7]3 years ago

3 0

Answer:

key concepts and summary. When electrons move from a higher energy level to a lower one, photons are emitted, and an emission line can be seen in the spectrum. Absorption lines are seen when electrons absorb photons and move to higher energy levels

Explanation:

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Your body uses about 24 grams of glucose to run cellular respiration. How many molecules does your body need for cellular respir

stealth61 [152]

10000000000303033830330291

3 0

3 years ago

The pressure at the center of the earth is probably greater than 3x106 atm, and the temperature there is about 4000 °C. What is

andrezito [222]

Answer:

The change in the Gibbs function of reaction on going from crust to core, dG=291442.4 J/mol

Explanation:

dG=vdp-sdT

Where T is the temperature .

P is the pressure.

S is entropy

V= 1cm3 =10-6 m3

P= 3*10∧6 atm = 3*10∧11 pa

The temperature at the center of the earth, Tc = 4*103 °C. : The temperature at the sufrace (crust) of the earth, Ts =298K.

Subistuting the values

dG = (10-6 *(3*1011-105) - (2.1(4373-298))

dG=291442.4 J/mol.

7 0

3 years ago

Based of the chemical reaction below, if you have 3.56x10^23 molecules of C3H8, how many liters of CO2 gas will be produced at S

LenaWriter [7]

Answer:

39.65L

Explanation:

First, let us calculate the number of mole present in 3.56x10^23 molecules of C3H8.

1 mole of any substance contains 6.02x10^23 molecules as discovered from Avogadro's hypothesis. This means that 1mole of C3H8 contains 6.02x10^23 molecules.

Now, if 1mole of C3H8 contains 6.02x10^23 molecules, then Xmol of C3H8 will contain 3.56x10^23 molecules i.e

Xmol of C3H8 = 3.56x10^23/6.02x10^23 = 0.59mole

The equation for the reaction is given below:

C3H8 + 5O2 —> 3CO2 + 4H2O

From the equation above,

1 mole of C3H8 produced 3moles of CO2.

Therefore, 0.59mole of C3H8 will produce = 0.59 x 3 = 1.77mole of CO2.

Now let us calculate the volume occupied by 1.77mole of CO2. This is illustrated below:

1 mole of any gas occupy 22.4L at stp.

Therefore, 1.77mole of CO2 will occupy = 1.77 x 22.4 = 39.65L

Therefore, 39.65L of CO2 are produced.

5 0

4 years ago

Consider an Al-4% Si alloy. Determine (a) if the alloy is hypoeutectic or hypereutectic, (b) the composition of the first solid

ozzi

Answer:

(a) Hypoeutectic

(b) Alpha solid, aluminium

(d) 97.6% α, 2.4% β

(e) 97.6% α, 2.4% β

(f) 97% α, 3% β

Explanation:

(a) The eutectic composition for Al Si alloy is 11.7 wt% silicon, therefore, an Al-4% Si alloy is hypoeutectic

(b) For the hypoeutectic alloy, aluminium, Al, is expected to form first, such that the aluminium content is reduced till the point it gets to the eutectic proportion of 11.7 wt% silicon

% α: Al (11 - 4)/(11 - 1) = 70% α

% L: Si 100 - 70 = 30% β

(d) At 576°C we have

α: 99.83% Si (99.83 - 4)/(99.83- 1.65) = 97.6% α

β: 1.65% Si (4 - 1.65)/(99.83- 1.65) = 2.4% β

(e) Primary α: 1.65% α (99.83 - 4)/(99.83 - 1.65) = 97.6% α

Eutectic 4% Si = 100 - 97.6 = 2.4% β

(f) At 25°C we have;

α%: (99.83 - 4)/(99.83 - 1) = 97% α

β%: 100 - 97 = 3% β.

8 0

4 years ago

The pressure on 150 mL of a gas is increased from 500 mm Hg to 700 mm Hg at constant temperature. What is the new volume of the

Ivanshal [37]

Answer:

Option A. 107 mL

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 150 mL

Initial pressure (P₁) = 500 mmHg

Final pressure (P₂) = 700 mmHg

Temperature = constant

Final volume (V₂) =?

The final volume of the gas can be obtained by using the Boyle's law equation as shown below:

P₁V₁ = P₂V₂

500 × 150 = 700 × V₂

75000 = 700 × V₂

Divide both side by 700

V₂ = 75000 / 700

V₂ = 107 mL

Therefore, the final volume of the gas is 107 mL.

4 0

3 years ago