Answer:
The answer is "Choice A".
Explanation:
In this question, the choice A is wrong because when the copper panels on houses produce a patina (copper oxide) through occur as a consequence of reactions from oxygen and water in the air, these reaction does not have low activation energy because lower activation energy that is stored in a faster response rate.
Answer: 
Explanation
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced combustion reaction for butane is,:
Answer:
4.1 moles of FeCl₃
Explanation:
The reaction expression is given as shown below:
2Fe + 3Cl₂ → 2FeCl₃
Number of moles of Cl₂ = 6.1moles
So;
We know that from the balanced reaction expression:
3 moles of Cl₂ will produce 2 moles of FeCl₃
Therefore 6.1moles of Cl₂ will produce 
= 4.1 moles of FeCl₃
The number of moles is 4.1 moles of FeCl₃
Explanation:
When water vapour changes to liquid water then this process is known as condensation.
For example, when lid is placed in a hot water filled pan then after sometime vapours appear on the surface of lid. When temperature of water decreases then water vapours convert into liquid form.
Thus, we can conclude that in condensation water vapor changes to liquid water.
Nonane (b) has the highest melting point.
-----------------------------
A caveat: I'm assuming that we're dealing with the straight-chain isomers of these alkanes (specifically pentane and nonane). The straight-chain isomer of pentane (<em>n</em>-pentane, CH3-[CH2]3-CH3) has a melting point of -129.8 °C; the straight-chain isomer of nonane (<em>n-</em>nonane, CH3-[CH2]7-CH3) has a melting point of -53.5 °C. The pattern holds as you go down (or up): The more carbon atoms, the higher the melting point. So, in decreasing order of melting points here, you'd have the following: nonane > pentane > butane > ethane.
However, one structural isomer of pentane, neopentane, has a melting point of -16.4 °C, which is <em>higher </em>that the melting point of <em>n</em>-nonane despite neopentane having the same molecular formula as its straight-chain isomer. Of course, you're not to blame for coming up with this question; this is just some extra info to keep in mind.
