# Chemical Forums

• May 21, 2018, 07:46:27 PM
• Welcome, Guest

•

Pages: [1]   Go Down

### AuthorTopic: Need some quick question help  (Read 1438 times) !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="https://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() {var po = document.createElement("script"); po.type = "text/javascript"; po.async = true;po.src = "https://apis.google.com/js/plusone.js";var s = document.getElementsByTagName("script")[0]; s.parentNode.insertBefore(po, s);})();

0 Members and 1 Guest are viewing this topic.

• Regular Member
• Mole Snacks: +0/-0
• Offline
• Posts: 23
##### Need some quick question help
« on: January 31, 2012, 05:23:33 PM »

Solid compound A decomposes according to the endothermic reaction:
A(s)-->2B(g) + C(g) Kp = 1.08 x 10-4

a) If 50.0 mmol of A(s) is placed in a 6.10-L sealed, evacuated flask at 25°C, calculate the total pressure in the flask at equilibrium.

well i plugged all these into the Pv=nRt formula

P=0.05mol(0.08206)(298K)/6.1L   and i get the wrong answer for the pressure
Logged

#### UG

• Full Member
• Mole Snacks: +134/-15
• Offline
• Gender:
• Posts: 822
##### Re: Need some quick question help
« Reply #1 on: January 31, 2012, 06:21:02 PM »

Can you write the equilibrium expression for this reaction? Note that A is a solid so it doesn't appear in this expression. All you need is this expression and some algebra to do the rest. Think about the ratio of B and C, then can you substitute some variable 'x' representing the partial pressure of C into the equilibrium expression? And then write the partial pressure of B in terms of 'x'? Hope this helps, but do get back if you are still stuck
Logged

Pages: [1]   Go Up

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.055 seconds with 23 queries.