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Label each of the following changes as a physical change or chemical change. Give evidence to support your answer.

SVEN [57.7K]

Answer:

A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.

Explanation:

Hello.

In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:

$2NO_2\rightarrow N_2+O_2$

As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.

Best regards.

3 0

3 years ago

A student left a sealed jar of water outside her home. Water can be a solid, liquid, or gas. When she put it outside, the water

GenaCL600 [577]

The water molecules received enough energy through the heat for them to change to a liquid state by unfixing themselves from their fixed positions.

3 0

3 years ago

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A sample of nitrogen gas occupies a volume of 2.55 L when it is at 755 mm Hg and 23 degrees Celsius. Use this information to det

ivolga24 [154]

<u>Answer:</u> The number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

<u>Explanation:</u>

To calculate the amount of nitrogen gas, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 755 mmHg

V = Volume of the gas = 2.55 L

T = Temperature of the gas = $23^oC=[23+273]K=296K$

R = Gas constant = $62.364\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of nitrogen gas = ?

Putting values in above equation, we get:

$755mmHg\times 2.55L=n\times 62.364\text{ L.mmHg }mol^{-1}K^{-1}\times 296K\\\\n=\frac{755\times 2.55}{62.364\times 296}=0.1043mol$

To calculate the pressure when temperature and volume has changed, we use the equation given by combined gas law.

The equation follows:

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1,V_1\text{ and }T_1$ are the initial pressure, volume and temperature of the gas

$P_2,V_2\text{ and }T_2$ are the final pressure, volume and temperature of the gas

We are given:

$P_1=755mmHg\\V_1=2.55mL\\T_1=23^oC=[23+273]K=296K\\P_2=?\\V_2=4.10L\\T_2=18^oC=[18+273]K=291K$

Putting values in above equation, we get:

$\frac{755mmHg\times 2.55L}{296K}=\frac{P_2\times 4.10L}{291K}\\\\P_2=\frac{755\times 2.55\times 291}{4.10\times 296}=461.6mmHg$

Hence, the number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

6 0

3 years ago

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When the disk of the moon masks the disk of the sun, it creates a _________ eclipse.

Dvinal [7]

When the disk of the moon mask the the disk of the sun,it creates a (solar) eclipse.

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3 years ago

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HELP

alisha [4.7K]

Answer:

3.beta particle

4.d

5.b

6.c

Explanation:

4 0

3 years ago