The correct answer is D - When burning a log, the wood combined its components with oxygen. if you could capture the products (CO2, H2O, C, CO, etc), you would have a greater mass than what you started with, burning the log combined the log's components with oxygen in order to burn it.

8 0

3 years ago

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Calculate the masses of oxygen and nitrogen that are dissolved in of aqueous solution in equilibrium with air at 25 °C and 760 T

shtirl [24]

Explanation:

Let us assume that the volume of given aqueous solution is 7.5 L.

Therefore, according to Henry's law, the relation between concentration and pressure is as follows.

C = $\frac{P}{K_{h}}$

where, pressure (P) = 760 torr = 1 atm

According to Henry's law, constants for gases in water at $25^{o}C$ are as follows.

$p(O_{2})$ = 0.21 atm = 0.21 bar

$p(N_{2})$ = 0.78 atm = 0.78 bar

$K_{h}$ for $O_{2}$ = $7.9 \times 10^{2} bar/mol$

$K_{h}$ for $N_{2}$ = $1.6 \times 10^{3} bar /mol$

Since, 21% oxygen is present in air so, its mass will be 0.21 g. Similarly, 78% nitrogen means the mass of nitrogen is 0.78 g.

Therefore, concebtrations will be calculated as follows.

$C(O_{2}) = \frac{0.21}{7.9 \times 10^{2}} = 2.66 \times 10^-4 mol/L$

$C(N_2) = \frac{0.78}{1.6 \times 10^3} = 4.875 \times 10^-4 mol/L$

Now, we will calculate the number of moles as follows.

$n(O_{2}) = 7.5 \times 2.66 \times 10^-4 = 1.995 \times 10^-3$ mol

$n(N_2) = 7.5 \times 4.875 \times 10^-4 = 3.66 \times 10^-3$ mol

As the molar mass of $O_2$ = 32 g/mol

Hence, mass of oxygen will be as follows.

Mass of $O_2 = 32 \times 1.995 \times 10^-3 \times 1000$

= 63.84 mg

As the molar mass of $N_{2}$ = 28

Mass of $N_{2} = 28 \times 3.66 \times 10^-3$ = 102.5 mg

Thus, we can conclude that mass of oxygen is 63.84 mg and nitrogen is 102.5 mg.

5 0

3 years ago

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Which best represents the reaction of calcium and zinc carbonate (ZnCO3) to form calcium carbonate (CaCO3) and zinc? Ca → ZnCO3

artcher [175]

Ca + ZnCO3 → CaCO3 + Zn

3 0

3 years ago

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Cierta cantidad de hidrogeno esta encerrada en una camara de platino a volumen constante. Cuando la camara se sumerge en un baño

salantis [7]

Answer:

-245.7°C es la temperatura del gas bajo 100 torr

Explanation:

Para resolver esta pregunta debemos hacer uso de la ley de Boyle que establece que la presión de un gas es directamente proporcional a la temperatura de este cuando el volumen permanece constante. La ecuación es:

P1T2 = P2T1

<em>Donde P es presión y T temperatura absoluta del estado inicial, 1, y final, 2.</em>

<em />

Reemplazando:

P1 = 1000torr

T2 = ? -Incógnita-

P2 = 100torr

T1 = 273K -Temperatura del hielo fundido = 0°C = 273K

1000torrT2 = 100torr273

T2 = 27.3K

27.3K - 273 =

<h3>-245.7°C es la temperatura del gas bajo 100 torr</h3>

<em />

3 0

3 years ago