Help with some Q's! ADA 2009

[meeka005]

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So I bought the web based version of ADA 2009 and completely regret it because I can't review the answers. Can someone help me with these questions?

Gchem
41. Exactly 492 g of kerosene are required to fill a certain container. If the density of the kerosene is 0.82 g (Media) mL –1 , and at the same temperature the density of mercury is 13.5 g (Media) mL –1 , then what mass of mercury, in grams, would be necessary to fill the container?

Since karosene and mercury are at the same temperature, they should have the same volume correct? So I would use D=m/v. I am getting mercurys' mass as (.492)(13.50)/(.82) I am not sure because I can't even see the answers -_-.

49. If a first-order reaction A → B has a half-life of 10.2 minutes and starts with a concentration of A = 1 mol (Media) L –1 , then what concentration of A will be present after 51.0 minutes of reaction?

 

[Kobebucsfan]

41) Yep, u got the correct answer 🙂


49) 1 - 1/2 - 1/4 - 1/8 - 1/16 - 1/32

answer is 1/32

b/c 51/10.2 = 5 so after 5 half lives u have 1/32 remaining.



i didn't purchase online 2009 DAT, so ur telling me that when u buy it online u can only look at questions and not the answer choices ? 😕

 

[meeka005]

Thank you! Yeah.. buy the print version. It takes about 3 weeks so order it early. The online version sucks.. I can only see the questions after the test. For the questions I got wrong, it doesn't even show me the correct answer. You can only view it for the four and a half hours you are taking the test.