chemistry questions

Archive SAT Subject Test Preparation
1

<p>The figure below is a force vs. displacement graph, showing the amount of force applied to an object by three different people. Al applies force to the object for the first 4 m of its displacement, Betty applies force from the 4 m point to the 6 m point, and Chuck applies force from the 6 m point to the 8 m point. Which of the three does the most work on the object?</p>

<pre><code>(A) Al
(B) Betty
(C) Chuck
(D) Al and Chuck do the same amount of work
(E) Betty and Chuck do the same amount of work
</code></pre>

<p>The figure… which wont copy here is:</p>

<p>a triangle with height from F= -4 till F = 0 and base from d = 0 to d = 4 (Al)</p>

<p>followed by a straight line from F = 0 to F = 4, which has x-displacement d = 4 till d = 6 (Betty)</p>

<p>followed by a horizontal line at F = 4 from d = 6 to d = 8 (Chuck)</p>

<p>…</p>

<p>the answer given is “c” , because -according to sparknotes- the work done by Al is in hte NEGATIVE direction…</p>

<p>but my question is, that if the question doesn’t even relate to direction, and since work is a scalar quantity anyway, doesn’t the work done by Al equal the one done by Chuck??..</p>

<hr>

<li><pre><code>Consider the following orderings and decide which of them give(s) a correct trend in ionization energy:
</code></pre>

<p>I. Al < Si < P < Cl
II. Be < Mg < Ca < Sr
III. I < Br < Cl < F
IV. Na+ < Mg2+ < Al3+ < Si4+</p>

<p>(A) I only
(B) III only
(C) I and II only
(D) I and IV only
(E) I, III, and IV only</p></li>
</ol>

<p>…</p>

<p>i think III is correct as well… is it?</p>

<hr>

<li> The balanced net ionic equation for the reaction of aluminum sulfate and sodium hydroxide contains which of the following terms?
(A) 3Al3+(aq)
(B) OH-(aq)
(C) 3OH-(aq)
(D) 2Al3+(aq)
(E) 2Al(OH)3(s)</li>
</ol>

<p>please do explain … =/</p>

2

<p>^^ that question 43 also stumped me, III is correct…sparknotes got it wrong</p>

3

<p>i think the last one is b-- OH-</p>

4

<p>is aluminum sulfate insoluble</p>

5

<p>yes aluminum sulfate is soluble</p>

6

<p>ok then i change my answer to E
because in net ionic, only the precipitate and its components are shown; this would be:
2Al-3 + 6OH- => 2Al(OH)2 </p>

<p>…i think</p>

7

<p>are all sulfates soluble except for those of group 2 metals?</p>

<p>btw, couldn’t it be either D or E? bc isnt it 2Al+3 + 6OH-----> 2Al(OH)3
both the precipitate and the 2Al+3 are choices</p>

8

<p>it cannot be either D or E. if it is E, you are saying that aluminum sulfate is insoluble and will not dissociate into ions in an aqueous solution–which it is not…in that case i think the answer is D</p>

9

<p>I used sparknotes last year and found 3 or 4 questions that had the wrong answer. I asked my teacher, and he agreed, so you could be right.</p>