Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 25 Apr 2015, 19:12

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# The rate of a certain chemical reaction is directly

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Senior Manager
Joined: 24 Oct 2006
Posts: 339
Followers: 1

Kudos [?]: 16 [0], given: 0

The rate of a certain chemical reaction is directly [#permalink]  16 Dec 2006, 23:02
The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemicl B present. If the concentration of chemical B is increased by 100% which of the following is the closest to the percentage change in the concentration of chemical A required to keep the reacton rate unchanged?

100% decrease
50% decrease
40% decrease
40% increase
50% increase

OA: D
Senior Manager
Joined: 08 Jun 2006
Posts: 342
Location: Washington DC
Followers: 1

Kudos [?]: 23 [0], given: 0

[#permalink]  17 Dec 2006, 00:00
Say A is the concentration of Chemical A and B is concentration of Chemical B
Then Rate = k * A^2 / B
B is increased by 100%, means the new conc is 2B
Rate = x^2 / 2B = A^2/B
=> new concentration of A = sqrt2 A
% = [(sqrt2*A â€“A)/A] * 100 = 41% increase
Director
Joined: 01 Oct 2006
Posts: 500
Followers: 1

Kudos [?]: 18 [0], given: 0

[#permalink]  17 Dec 2006, 00:59
anindyat wrote:
Say A is the concentration of Chemical A and B is concentration of Chemical B
Then Rate = k * A^2 / B
B is increased by 100%, means the new conc is 2B
Rate = x^2 / 2B = A^2/B
=> new concentration of A = sqrt2 A
% = [(sqrt2*A â€“A)/A] * 100 = 41% increase

A2..
Same approach as anindyat but used numbers instead.
Senior Manager
Joined: 24 Oct 2006
Posts: 339
Followers: 1

Kudos [?]: 16 [0], given: 0

[#permalink]  17 Dec 2006, 08:01
I understand. Thank you.
[#permalink] 17 Dec 2006, 08:01
Similar topics Replies Last post
Similar
Topics:
The rate of a certain chemical reaction is directly 4 20 Jan 2007, 23:10
The rate of a certain chemical reaction is directly 1 07 May 2006, 09:18
The rate of a certain chemical reaction is directly 4 04 Apr 2006, 01:38
The rate of a certain chemical reaction is directly 3 27 Aug 2005, 10:04
6 The rate of a certain chemical reaction is directly 8 07 Aug 2005, 20:00
Display posts from previous: Sort by

# The rate of a certain chemical reaction is directly

 Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.