Label each of the following changes as a physical change or chemical change. Give evidence to support your answer.
1 answer:
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:
As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.
Best regards.
You might be interested in
Specif gravity = density of the material / density of water
density of the material = specific gravity * density of water
density of gold = 19.3 * 1 g/mL = 19.3 g/mL
density = mass / volume ==> Volume = mass / density
Volume = 0.4 kg * 1000 g/kg / 19.3 g/mL = 20.725 mL
Length of one side of the cube =![\sqrt[3]{20.725 {cm}^{3} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B20.725%20%7Bcm%7D%5E%7B3%7D%20%7D%20)
= 2.75 cm
Pass cm to inches
2.75 cm * 1 inch / 2.54 cm = 1.08 inch
density of the material = specific gravity * density of water
density of gold = 19.3 * 1 g/mL = 19.3 g/mL
density = mass / volume ==> Volume = mass / density
Volume = 0.4 kg * 1000 g/kg / 19.3 g/mL = 20.725 mL
Length of one side of the cube =
Pass cm to inches
2.75 cm * 1 inch / 2.54 cm = 1.08 inch
The answer is 1/16.
Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1.
,
where:
<span>n - a number of half-lives
</span>x - a remained fraction of a sample
2.
where:
<span>
- half-life
</span>t - <span>total time elapsed
</span><span>n - a number of half-lives
</span>
So, we know:
t = 10 min
<span> = 2.5 min
We need:
n = ?
x = ?
</span>
We could first use the second equation to calculate n:
<span>If:
,
</span>Then:
⇒
⇒
<span>
</span>
Now we can use the first equation to calculate the remained fraction of the sample.
<span>
</span>⇒
<span>⇒
</span>
Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1.
where:
<span>n - a number of half-lives
</span>x - a remained fraction of a sample
2.
where:
<span>
</span>t - <span>total time elapsed
</span><span>n - a number of half-lives
</span>
So, we know:
t = 10 min
<span>
We need:
n = ?
x = ?
</span>
We could first use the second equation to calculate n:
<span>If:
</span>Then:
⇒
⇒
</span>
Now we can use the first equation to calculate the remained fraction of the sample.
<span>
</span>⇒
<span>⇒