At 5 atmospheres pressure and 70*C, how many moles are present in 1.5L of O2 gas?

<p>this question is in my barrons sat ii chem book and i think the answer they provide is wrong. i just want to verify</p>

<p>use PV=nRT
convert 70 C to Kelvins
and use the .082 constant</p>

<p>thats what i did. i want the answer</p>

<p>PV= nRT
5(1.5)=n(.0821)(343)
7.5= 28.16n
.266 mol=n</p>

<p>yeah, I was wondering about this question too because Barrons used 0.220 as the constant for r...and I'm not sure why.</p>

<p>It seems like there are quite a few mistakes in the Chapter 5 review section (#10, # 14).</p>

<p>Also for #7 in the chapter 5 review, I thought A would be the answer since the question asks which metal would react most vigorously in a "dilute acid solution" and so according to the activity chart on page 102, I picked A) zinc. Could someone further explain why D was the answer?</p>

<p>Can someone also please explain the answer to #11 on page 117?</p>

<p>Thanks.</p>

<p>bump bump bump!</p>