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May 23, 2024, 12:14:56 pm

Author Topic: PRELIM YEARLY HELP  (Read 1158 times)  Share 

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beeangkah

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PRELIM YEARLY HELP
« on: September 12, 2017, 11:13:44 am »
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Please help with this question :)

Answer is A btw but how?
« Last Edit: September 12, 2017, 11:17:24 am by beeangkah »

Natasha.97

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Re: PRELIM YEARLY HELP
« Reply #1 on: September 12, 2017, 11:55:37 am »
+4
Please help with this question :)

Answer is A btw but how?


Hi!
- Gay-Lussac: Ratios of gas volumes involved in a chemical reaction are expressed by small, whole numbers
-  Avogadro's law: Equal volumes of gases at the same temperature and pressure contain equal numbers of particles
        - Ratio of molecules is the same as the coefficients of the balanced chemical equation

In the question, all volumes were measured at the same temperature and pressure (25 degrees and 100kPa), and the coefficients represents the volume ratio of gases. The ratio of methane to carbon dioxide is 1:1, and as the reaction goes to completion, the only gas present will be carbon dioxide. Therefore, the volume of gases present is 100ml.

Hope this helps
« Last Edit: September 12, 2017, 12:15:37 pm by Jess1113 »
Life is weird and crazy as heck but what can you do?

beeangkah

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Re: PRELIM YEARLY HELP
« Reply #2 on: September 12, 2017, 12:22:42 pm »
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Hi!
- Gay-Lussac: Ratios of gas volumes involved in a chemical reaction are expressed by small, whole numbers
-  Avogadro's law: Equal volumes of gases at the same temperature and pressure contain equal numbers of particles
        - Ratio of molecules is the same as the coefficients of the balanced chemical equation

In the question, all volumes were measured at the same temperature and pressure (25 degrees and 100kPa), and the coefficients represents the volume ratio of gases. The ratio of methane to carbon dioxide is 1:1, and as the reaction goes to completion, the only gas present will be carbon dioxide. Therefore, the volume of gases present is 100ml.

Hope this helps

Thanks so much!
Do you also mind helping with this? :)


MisterNeo

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Re: PRELIM YEARLY HELP
« Reply #3 on: September 12, 2017, 12:32:09 pm »
+4
Thanks so much!
Do you also mind helping with this? :)


-Find the moles of solute in the 10mL.
-Find the concentration of the new solution by dividing by the 250mL.

beeangkah

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Re: PRELIM YEARLY HELP
« Reply #4 on: September 12, 2017, 12:58:51 pm »
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Thank youuuu

Also this one, I always struggle with calculations haha  :'(


MisterNeo

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Re: PRELIM YEARLY HELP
« Reply #5 on: September 17, 2017, 08:33:25 pm »
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Thank youuuu

Also this one, I always struggle with calculations haha  :'(

Sorry for the late reply

The drop in the graph shows the limiting reagent running out and no more barium sulfate being produced.
Sodium ions should be doubled as it has two moles per sodium sulfate mole. Barium sulfate removes barium ions from solution, so don't include that. Answers would be nice :)