need bio f.h.i help. (1 Viewer)

[Riot09]

basically our teacher told us to come with a way to demonstrate how surface area can change the rate of reaction,using: marble chips,calcium carbonate powder,dilute hydrochloric acid,test tubes with stoppers and with and without side arms,lime water or calcium hydroxide solution,10ml measuring cylinder and a test tube rack.

some background information

calcium carbonate reacts with hcl acid to produce c02 and cacl2.carbon dioxide may be detected by "bubbling" (i d.k what this means) the gas into lime water.if co2 is present ,the lime water turns milky.calcium carbonate may be obtained either as marble chips or as a powder.

i don't know what to do.

thnx.

 

[Curkz]

Wait so you don't know what prac to follow or what to test for? I'm lost on what you're trying to achieve.

I do remember doing a comparison though,

Marble Chips as solid chips in one test tube with the same amount of acid in each test tube.

Then you add both to each test tube with acid and record the time which had the fastest overall reaction...

It was the powder obviously.

Something like that or ? explain please

 

[octopie]

Curkz got the main idea, powder has a faster reaction than the chip.

If "how surface area can change the rate of reaction" is all you're investigating, really you don't need the limewater and the stoppers with gas delivery tubes, unless they're only there to prove that a reaction occurs.. but you can conclude that from observations of the chip/powder dissolving. "Bubbling" means putting the tube into the limewater and letting the CO2 from the test tube escape into the limewater and "bubble" its way out into the surrounding air.

So your method would involve (roughly) the same mass of powder and chip/s, put into the same amount of HCl; chips in one tube, powder in the other. Time the reactions. Powder has a larger SA for the volume of calcium carbonate used than the chip, and your conclusion is deduced from there.

Hope I helped~

 

[Riot09]

thanks octopie,and curks it was just the experimental design ( i didn't know what i needed to do with the materials and apparatus) however thanks anyway for Ur help.

 

[octopie]

No probs =)

 

[Sleight_of_Hand]

a quick unrelated (not trolling) question: is birrong boys as bad as it has been portrayed?

 

[Riot09]

both yes and no."most of the time the boys are well behaved", especially now compared to a few years ago. in behavior our school is alright however academically we could do better.

-in my personal opinion if u go 2 birrong it feels like a normal school