<p>There was a question in Barron's SAT II book that confused me:
Practice Test I Problem 55:
40 g of NaOH dissolved in enough water to make 1 L of solution. What is the molarity of the solution?
The answer is .25 M. </p>
<p>The explanation says to divide 10 by 40 to get .25mol which you then divide by 1L to get .25M. Where does the 10 come from?!</p>
<p>Haha I saw that too... it's a mistake. It's 40 not 10.</p>
<p>i dont know.</p>
<p>!!!!!!</p>
<p>I didn't know test prep books could make mistakes. This decreases the god-like status Barron's has in my eyes. </p>
<p>Thanks!
(The answer would be 1M then, right?)</p>
<p>No problem. Trust me there are a lot of prep books with mistakes in them. Just found another one on Barron's actually... wrong letter answer in one of the chapter's practice.</p>
<p>Yep, 1M is right :]</p>
<p>Barron's makes mistakes, check out AP Physics C prep book if you dont believe me</p>