How Does Increasing NaOH Mass Affect Heat Evolution in a Lab Experiment?

[Dooh]

I have been spending nearly 3 hours on this lab write up that is due tomorrow. since i had missed a couple days of school, there are somethings that i was not introduced to therefore this is kinda hard for me. I managed to figure out most part but this is what I'm stuck on right now.

Part of the experiment requires us to mix 2g of NaOH with water and calculate the amount of heat evolved. This question asked: suppose to had used 8g of NaOH instead, what would have been the number of calories evolved in the experiment and what effect would this have on change if Heat? I keep thinking its four times more but that's going to only apply to the temperature. So is there anyone on this late at night taht can help me?

 

[chem_tr]

Sodium hydroxide gives x calories per mole upon dissolution; so 2 grams of NaOH (m.w.=40 grams/mol) will give Q₁=x/20 calories, since this is 1/20 moles. If you use 8 grams of NaOH, you'll get Q₂=x/5 calories. This is because 8 grams of NaOH is 0.2 moles.

 

[ravenprp]

Hi there,

I understand that you are struggling with your lab write up that is due tomorrow. It can be tough to catch up on missed material and complete assignments on a tight deadline. However, I suggest taking a deep breath and approaching this step by step.

Firstly, it's great that you managed to figure out most of the lab write up. That shows determination and effort on your part. Now, let's focus on the part that you are stuck on.

To answer the question about the amount of heat evolved, we need to use the formula Q = m x c x ΔT, where Q is the heat evolved, m is the mass of the substance (in this case, NaOH), c is the specific heat capacity, and ΔT is the change in temperature.

Since you were asked to calculate the amount of heat evolved if 8g of NaOH was used instead of 2g, we can use the same formula but with a different value for m. The specific heat capacity and change in temperature will remain the same.

So, if we plug in the values, we get Q = 8g x c x ΔT. Since the specific heat capacity and change in temperature are constant, the only variable that changes is the mass (m). Therefore, the amount of heat evolved would be four times more (8g/2g = 4).

As for the effect on the change in heat, it would still be the same as the specific heat capacity and change in temperature are constant. The only difference would be the amount of heat evolved, which we have already calculated.

I hope this helps you with your lab write up. Remember to double-check your calculations and make sure to cite your sources. Good luck!