sat ii chem question

Test Preparation SAT Subject Test Preparation
1

<p>this question is troubling me...
its on the official sat prep booklet</p>

<p>All of the following statements are true about carbon dioxide EXCEPT</p>

<p>a) it can be prepared by the action of acid on limestone
b) it is used to extinguish fires
c) it dissolves in water at room temperature
d) it sublimes rather than melts at 20 degrees C and 1 atm
e) it is less dense than air at a given temperature and pressure</p>

<p>my first choice was c because isn't CO2 nonpolar and water is polar? and only like dissolves like?
but then the answer said e which also makes sense</p>

<p>also is there anyone to study for these types of questions because they are not in the prep books like sparknotes and PR</p>

2

<p>Even I gravitated to C..anyone?</p>

<p>CO2 can't dissolve in water at room temp unless of course the pressure is increased...THAT'S IT! Hence, its E...this one's tricky. It didn't say anything about the pressure!...</p>

3

<p>hmm..I was guessing C too...'cause we all know that CO2 doesn't dissolve in water...could it be because that density never changes for a certain substance no matter the condition?</p>

4

<p>for #2 wwhy does 0.1M of CH3OH have a higher pH than 0.1M of KOH??</p>

<p>sry read the wrong key</p>

5

<p>Isn't that Methanol...and does anyone know how to do number 19?</p>

6

<p>co2 does dissolve in water i'm sure what about soda or carbonated water</p>

7

<p>well ksp = product a concentration x product b concentration</p>

<p>therefore
1x10^-8= concentration of pb 2+ times concentration of so4 2-
since pb 2+ and so42- are produced at a 1 to 1 ratio, just take the square root of 1x10^-8</p>

8

<p>Anyone know how to do 19? I used square root and I got the right answer but is it the right way?</p>

<p>Edit: thanks..</p>

9

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<p>i'm pretty sure i did this experiment one time where you put some kind of acid/base indicator in water and blow bubbles through a straw into it. The water changes this yellow color to signify that its an acid or whatever since your exhaled CO2 is dissolving into the water..
that's why i would reason C is true anyway.</p>

10

<p>Yup I guess pressure is the key point.
Found this on a website</p>

<p>"Although Carbon Dioxide (CO2) is a non-polar molecule, it does dissolve in water to form a solution under special circumstances. Carbon Dioxide is dissolved in water under pressure in carbonated drinks. When the pressure is released by opening the bottle or can, the CO2 gas quickly separates from the water in the form of bubbles."</p>