Answer: Event 1 is an example of a physical change and Event 2 is an example of a chemical change.
Explanation: Physical change is one in which there is no change in chemical composition of the substance. There is only a change in phase change.
Chemical change is a change in which there is a change in chemical composition and there might or might not be a phase change.
On Boiling, the water molecules remain bonded in the same form and only covert from liquid to gaseous form, thus is a physical change.
On Rusting of iron nail, the iron changes to iron oxide by combining with oxygen, there is a rearrangement of atoms and thus is a chemical change.
Answer:
Mass fraction = 0.08004
Mole fraction = 0.0377
Explanation:
Given, Mass of NaOH = 8.70 g
Mass of solution = 8.70 + 100 g = 108.70 g
= 0.08004
Molar mass of NaOH = 39.997 g/mol
The formula for the calculation of moles is shown below:
Thus,
Given, Mass of water = 100 g
Molar mass of water = 18.0153 g/mol
The formula for the calculation of moles is shown below:
Thus,
So, according to definition of mole fraction:
It will appear to be the color red
Answer:
This tells us the radial velocity of the object and that the object is approaching or coming towards us.
Explanation:
Certain chemicals radiate with particular wavelengths or colors when their temperature is raised or when they are charged electrically. Also observable are dark strokes separating the spectrum known as absorption lines
These spectral lines of chemicals are well known as stated above and from the phenomenon of Doppler effect, spectroscopy can be used to detect the movement of a distant object by the change of the emitted frequency of the wavelength
The Doppler effect is used in calculating the radial velocity of a distant object due to the fact that an approaching object compresses its emitted signal wavelength while a receding object has a longer wavelength than normal
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Answer:</h3>
8CO₂
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Explanation:</h3>
We are given;
- Butane is a hydrocarbon in the homologous series known as alkane.
We are required to determine the other product produced in the combustion of butane apart from water.
- We know that the complete combustion of alkane yields carbon dioxide and water.
- Therefore, combustion of butane will yield carbon dioxide and water.
- The balanced equation for the complete combustion of butane will be;
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
