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3 years ago

The atmospheric gases in the thermosphere are heated _____. Pick the best one.

Chemistry

2 answers:

Trava [24]3 years ago

7 0

Answer:

Hi! It is acually directly by the sun.

Explanation:

lozanna [386]3 years ago

4 0

by radiation from the Earth's surface

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A gas used to extinguish fires is composed of 75 % CO2 and 25 % N2. It is stored in a 5 m3 tank at 300 kPa and 25 °C. What is th

tatyana61 [14]

Answer : The partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

Explanation :

As we are given 75 % $CO_2$ and 25 % $N_2$ in terms of volume.

First we have to calculate the moles of $CO_2$ and $N_2$ .

$\text{Moles of }CO_2=\frac{\text{Volume of }CO_2}{\text{Volume at STP}}=\frac{75}{22.4}=3.35mole$

$\text{Moles of }N_2=\frac{\text{Volume of }N_2}{\text{Volume at STP}}=\frac{25}{22.4}=1.12mole$

Now we have to calculate the mole fraction of $CO_2$ .

$\text{Mole fraction of }CO_2=\frac{\text{Moles of }CO_2}{\text{Moles of }CO_2+\text{Moles of }N_2}$

$\text{Mole fraction of }CO_2=\frac{3.35}{3.35+1.12}=0.75$

Now we have to calculate the partial pressure of the $CO_2$ gas.

$\text{Partial pressure of }CO_2=\text{Mole fraction of }CO_2\times \text{Total pressure of gas}$

$\text{Partial pressure of }CO_2=0.75mole\times 300Kpa=225Kpa=225Kpa\times \frac{0.145\text{ psia}}{1Kpa}=32.625\text{ psia}$

conversion used : (1 Kpa = 0.145 psia)

Therefore, the partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

3 0

3 years ago

What are 2 metric system units for measuring liquid volume?

Step2247 [10]

Answer:

milliliters and liters.

3 0

3 years ago

When you put an ice cube into a glass of room temperature water, why does the water get cold?

mel-nik [20]

The water gets cold because the ice cube is endothermic. Which means it takes in heat. It takes the warmth from the water and melts the ice cube which the ice cube releases coldness which cools down the water.

6 0

3 years ago

El fluoruro de hidrógeno HF que se utiliza en

Blizzard [7]

Answer:

25.6g de HF son producidos

Explanation:

...¿Cuánto HF es producido?

Para resolver este problema debemos convertir la masa de cada reactivo a moles usando su masa molar. Como la reacción es 1:1, el reactivo con menor número de moles es el reactivo limitante. Con las moles del reactivo limitante podemos obtener las moles de HF y su masa así:

Moles CaF2:

Masa molar:

1Ca = 40g/mol

2F = 19*2 = 38g/mol

40+38 = 78g/mol

50g CaF2 * (1mol/78g) = 0.641 moles CaF2

Moles H2SO4:

Masa molar:

2H = 2g/mol

1S = 32g/mol

4O = 64g/mol

98g/mol

100g H2SO4 * (1mol / 98g) = 1.02 moles H2SO4

Como las moles de CaF2 < Moles H2SO4: CaF2 es reactivo limitante.

Moles HF usando la reacción:

0.641 moles CaF2 * (2mol HF / 1mol CaF2) = 1.282 moles HF

Masa HF:

Masa molar:

1g/mol + 19g/mol = 20g/mol

1.282 moles HF * (20g/mol) =

<h3>25.6g de HF son producidos</h3>

8 0

3 years ago

What is the molar mass of CaCl2?

Aleks04 [339]

Answer: The molar mass of the given compound is $1.11\times 10^2 g/mol$

Explanation:

In molecular formula of $CaCl_2$ there are two chlorine atoms and one calcium atom.

The atomic mass of the calcium = 40.07 g/mol

The atomic mass of chlorine = 35.5 g/mol

Molar mass of the guven compound is :

$40.07 g/mol + 2\times 35.5 g/mol=111.07 g/mol\approx 1.11\times 10^2 g/mol$

The molar mass of the given compound is $1.11\times 10^2 g/mol$

8 0

3 years ago