SAT II Chemistry questions:

Test Preparation
1

<p>Here are some of the Chemistry questions I got wrong, and that I don't know how to do (These came from BB):</p>

<p>44.) Which of the following statements is true concerning a saturated solution of a salt at a constant temperature?</p>

<p>(A) The concentrations of salt and solvent are usually equal.
(B) The amount of dissolved salt is constant.
(C) Addition of solid salt shifts the equilibrium, which results in an increase in amount of dissolved salt.
(D) The solution is unstable and sudden crystallization could occur.
(E) At the same temperature, a saturated solution of any other salt has the same concentration.</p>

<p>[I chose (D) because in Chemistry class I remembered an experiment where we added salt to a supersaturated solution, and crystals were formed]</p>

<p>48.) An active ingredient in common household bleach solutions is most likely to be which of the following?</p>

<p>(A) NaCl
(B) NaClO
(C) NaHCO3
(D) Na2SO4
(E) HC2H3O2</p>

<p>[I chose (E) because I thought it could have been a base, and bases are usually cleaning products]</p>

<p>Thanks for all the help and explanations!</p>

2

<p>Lol, if you thought it was a base, why did you choose acetic acid haha but,
Bleach contains strong oxidizing agents, meaning that it contains ingredients that really want to be reduced(really wants gain electrons) so we look at formal charges and we try to look at trends like the atoms on the right of the Periodic table want to have -charges and atoms on the left have +charges.
NaCl is just salt, everything is fine with this cuz Sodium want to be a +1 and Chlorine a -1
NaClO, this is an interesting specimine. O usually is designated the Ox # first and is almost always a -2 charge then Na is usually a +1 thus in order to balance Cl must be +1. WHOA!! thats not right. Cl wants to be a -1. thus it really really wants to gain 2 electrons to be a -1. this thing will rip electrons away from alot of things. This is a darn good oxidizing agent.
NaHCO3 is just baking soda and everything is balanced out
Na2SO4 is not really very reactive, slightly basic, but is perfectly fine with Sulfur having a +6.</p>

<p>Uhh 44, I think its B, because no more salt will dissolve; and thus the amount of dissolved salt is constant. Why the salt will no longer dissolve, the solution is already saturated and the temperature is constant.</p>

<p>I just started AP Chem, I want to take Chem Subj. test next year :D</p>