PH3-4. It says suggest so try getting a close and appropriate answer after adding an acid to an alkaline.
The answer has to depend on the mass of the copper that you're trying to melt.
But there is a formula which you can calculate the energy required if you have the information of the mass. This formula requires the value called specific latent heat of fusion, which is the energy required to melt or freeze a specific mass of copper without changing its temperature but change its state.

E is the total energy required, m is the mass, and lv is the specific latent heat of fusion of copper.
Usually, in questions, lv is given. But we can also look it up online which is around 205kJ kg^-1
this means, to melt or freeze a copper, we need to work the mass multiplied by 205kJ in order to calculate its total energy needed or released.
Answer:
New kinds of products forms and the reaction is not easily reversible.
Explanation:
The only way to be certain that a chemical change has occurred is by finding out if new kinds of products have been formed.
A chemical change is a change in which new kinds of matter is formed. It is always accompanied by energy changes.
The process is not easily reversible.
Examples of chemical changes are combustion, rusting of iron, precipitation and souring of milk.
The answers that apply include;
- A saturated fatty acid with a greater molar mass has a higher melting point than a saturated fatty acid with a low molar mass
- A saturated fatty acid has a higher melting point than an unsaturated fatty acid
Saturated acids do not have double bonds in their hydrocarbon tails. Therefore, because there are no kinks in the chains, the chains are well compacted due to numerous hydrogen bonds between each. The larger the chains (directly proportional to molar mass), the higher the melting point of these fats.
Answer:
- <em><u>Step 2 (the slow step).</u></em>
Explanation:
The rate-determining step is always the slow step of a mechanism.
That is so, because it is the slow step which limits the reaction.
Imaging that for assembling a toy you have process of three steps:
- 1. order ten pieces, which you can do in 1 minute: meaning that you can order order the pieces for 60/1 = 60 toys in 1 hour.
- 2. glue the pieces and hold the toy until the glue hardens, which takes 1 hour: meaning finishingh 1 toy in 1 hour.
- 3. pack the toy, which takes 2 minutes: meaning that you can pack 60/2 = 30 toys in one hour.
The time to glue and hold one toy until the glue hardens determines that you can assemble 1 toy in 1 hour and not 60 toys or 30 toys.
Thus, the step that determines the rate at which the reaction happens is the slowest step: step 2.