6th Edition, 8.99

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Hai-Lin Yeh 1J
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Joined: Fri Sep 28, 2018 12:16 am
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6th Edition, 8.99

Postby Hai-Lin Yeh 1J » Sat Feb 09, 2019 12:13 pm

Hydrochloric acid oxidizes zinc metal in a reaction that produces hydrogen gas and chloride ions. A piece of zinc metal of mass 8.5 g is dropped into an apparatus containing 800.0 mL of 0.500 m HCl(aq). If the initial temperature of the hydrochloric acid solution is 25 C, what is the final temperature of this solution? Assume that the density and molar heat capacity of the hydrochloric acid solution are the same as those of water and that all the heat is used to raise the temperature of the solution.

Why is the specific heat capacity negative when we calculate mc(deltaT)? Also, I can understand why we need to calculate the limiting reactant here, but how do we know when to do it for other problems or not? For example, what makes this problem different from the others that we need to calculate the limiting reactant?

Iris Bai 2K
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am

Re: 6th Edition, 8.99

Postby Iris Bai 2K » Sun Feb 10, 2019 5:38 pm

If the specific heat capacity is the same as water, it shouldn't be negative. The constant is on the formula sheet. Usually, a problem will tell you that one reactant is in excess; if it doesn't, you probably need to find the limiting reactant.

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