GAMSAT Forum - Gold Standard GAMSAT Prep

The Only Prep You Need

GS-Heaps 2 Section III- Q69

GS-Heaps 2 Section III- Q69

Postby lieba » Sat Jul 28, 2018 11:55 am

Hi,

If i could get further clarification as to why Q69 is B would be great, i don't quite understand the reasoning behind obtaining B as an answer (I had D)?

Kind regards,
Lieba
lieba
 
Posts: 3
Joined: Mon Jul 09, 2018 1:41 pm

Re: GS-Heaps 2 Section III- Q69

Postby goldstanda3269 » Sat Jul 28, 2018 11:39 pm

lieba wrote:If i could get further clarification as to why Q69 is B would be great, i don't quite understand the reasoning behind obtaining B as an answer (I had D)?


"When cement sets, it produces heat."

The second part is assumed knowledge: a reaction that produces heat is exothermic and so delta H is negative.

So the only issue is to reason the meaning of "When cement sets". For this, you can pull from personal experience, for example, having seen cement being poured from a truck (a liquid form) to produce something solid (a sidewalk, a wall for a building, etc.).

Entropy is a measure of randomness. Increased entropy (positive) means that something is becoming more random, for example: solid -> liquid -> gas. Since cement setting suggests liquid to solid, entropy decreases and is thus negative.

FYI: Here is the forum section for the Heaps-2 exam viewforum.php?f=72 Each exam has its own subforum. The above question will eventually be moved to the subforum.

Our next free webinar: https://www.wiziq.com/online-class/5566 ... ng-webinar

Good luck with your studies!
goldstanda3269
 
Posts: 1672
Joined: Wed Aug 25, 2010 10:59 pm


Return to General Questions

Who is online

Users browsing this forum: No registered users and 1 guest