AP Chem frq help?

Test Preparation AP Sciences
1

<p>Hi! I just have one question. Could someone please help me with it? It’s from the 2012 AP Chem exam:</p>

<p>In a laboratory experiment, Pb and an unknown metal Q were immersed in solutions containing aqueous ions of unknown metals Q and X. The following reactions summarize the observations.</p>

<p>Observation 1: Pb(s) + X2+(aq) –> Pb2+(aq) + X(s)
Observation 2: Q(s) + X2+(aq) –> no reaction
Observation 3: Pb(s) + Q2+(aq) –> Pb2+(aq) + Q(s)</p>

<p>(a) On the basis of the reactions indicated above, arrange the three metals, Pb, Q, and X, in order from least reactive to most reactive on the lines provided below.</p>

<p>I honestly have no clue lol. Thanks!!!</p>

2

<p>I believe it’s Q > X > Pb or X >Q > Pb. (I’m leaning towards the first.) Either way Pb is at the end.</p>

3

<p>It’s the first one. </p>

<p>This question is based on the activity series of metals, and since Pb will replace both ions of Q and X, it’s the most reactive. Then, since Q will not replace X, X is more reactive than Q. I say replace because usually the activity series has to do with single displacement reactions.</p>