Answer:
Carbon dioxide
Explanation:
Neither helium nor carbon dioxide has a molecular dipole, so their strongest van der Waals attractive forces are London forces.
Helium is a small spherical atom with only a two electrons, so its atoms have quite weak attractions to each other.
CO₂ is a large linear molecule. It has more electrons than helium, so the attractive forces are greater. Furthermore, the molecules can align themselves compactly side-by-side and maximize the attractions (see below).
For example. CO₂ becomes a solid at -78 °C, but helium must be cooled to -272 °C to make it freeze (that's just 1 °C above absolute zero).
The correct answers are
-formation of a precipitate
-bubble formation
-color change
-temperature change
-odor formation
The only one that isn’t correct is change in state of matter. A change in a state of matter does not mean it’s a chemical change. For example, water boiling so it turns into gas is not a chemical change, and is a physical one. Also, water can freeze and turn into ice, which is also still a physical change. If something changes state of matter, it does not necessarily mean it’s a chemical change.
<u>Answer:</u> The amount of heat released is 56 MJ.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of = 12 kg = 12000 g (Conversion factor: 1 kg = 1000 g)
Molar mass of = 30 g/mol
Putting values in above equation, we get:
The chemical reaction for hydrogenation of ethene follows the equation:
By Stoichiometry of the reaction:
When 1 mole of ethane releases 140 kJ of heat.
So, 400 moles of ethane will release = of heat.
Converting this into Mega joules, using the conversion factor:
1 MJ = 1000 kJ
So,
Hence, the amount of heat released is 56 MJ.
Answer:
C. product costs and expensed when the goods are sold
Explanation: