HSC Chemistry Question Thread

[RuiAce]

Hello! Please and thank you for the help!

I have a titration calculation and I'm not entirely sure what I'm doing.

If it takes 50mL of 0.5M KOH to completely neutralise 125 mL of sulfuric acid solution (H₂SO₄), what is the concentration of the H₂SO₄ solution.

[QC]

Do you want one of these? I can try discussing it with some higher authorities.

Yeah, as I said, I think if active, it is possibly better than past papers and I think it is useful especially for long response/harder questions that may be hard for one person to objectively mark.

[bsdfjnlkasn]

Do you want one of these? I can try discussing it with some higher authorities.

This sounds sick!!!

[RuiAce]

This sounds sick!!!

It's up. And it needs more participants :P

[bsdfjnlkasn]

It's up. And it needs more participants :P

Just posted 

[morning Glory]

Hi! I'm currently doing Chemical Monitoring and Management and I was wondering what's the difference between Total Dissolved Solids and Concentration of common ions. I know that the Concentration of common ions is for nitrates and phosphates whereas TDS is mainly measuring salts and other metal ions. However, I believe that some nitrates are soluble in water, so would these still be classified in Conc of common ions or in TDS? Also, couldn't the ions in TDS be considered 'common' ions?

[beau77bro]

hello, i was wondering if jake still has those chemistry worksheets he talked about at the lecture? im making my own now however i dont quite remember what i dont quite remember so his stuff would be super helpful as a template

a link or something would be fine, if not still thankyou

[jakesilove]

Hi! I'm currently doing Chemical Monitoring and Management and I was wondering what's the difference between Total Dissolved Solids and Concentration of common ions. I know that the Concentration of common ions is for nitrates and phosphates whereas TDS is mainly measuring salts and other metal ions. However, I believe that some nitrates are soluble in water, so would these still be classified in Conc of common ions or in TDS? Also, couldn't the ions in TDS be considered 'common' ions?

Hey! The main difference is that the concentration of common ions test refers to a specific ion. So, you might try to figure out the specific concentration of nitrates in a waterway, using appropriate tests. However, total dissolved solids refers to ANY solid, and is expressed as a percentage by weight. This is used to determine turbidity, and general health of the waterway. Another thing to note is that ALL nitrates are soluble in water. If you were to test specifically for nitrates, then you would classify it as a common ion, but if you were testing for ALL impurities then it would fall within TDS. Does that make sense? Common ions often fall WITHIN TDS.

[jakesilove]

hello, i was wondering if jake still has those chemistry worksheets he talked about at the lecture? im making my own now however i dont quite remember what i dont quite remember so his stuff would be super helpful as a template

a link or something would be fine, if not still thankyou

Hey! I don't actually have Chemistry worksheets available, however I have written an article explaining the technique which you can find HERE. Whilst the article refers to Modern History, just do the same thing for Chemistry Feel free to post your worksheets here, would be happy to take a look!

[beau77bro]

ok sweet thankyou for the help and great advice. you guys rock im gonna go read that now thankyou lots.

[jakesilove]

ok sweet thankyou for the help and great advice. you guys rock im gonna go read that now thankyou lots.

No problem! Always happy to help

[morning Glory]

Hey! The main difference is that the concentration of common ions test refers to a specific ion. So, you might try to figure out the specific concentration of nitrates in a waterway, using appropriate tests. However, total dissolved solids refers to ANY solid, and is expressed as a percentage by weight. This is used to determine turbidity, and general health of the waterway. Another thing to note is that ALL nitrates are soluble in water. If you were to test specifically for nitrates, then you would classify it as a common ion, but if you were testing for ALL impurities then it would fall within TDS. Does that make sense? Common ions often fall WITHIN TDS.

Right, that makes a lot more sense, thank you! Have a nice day

[RangaTurtle]

Hello. I need to compare dry cell to lithium cell batteries for homework but having trouble finding what is the chemical reaction of a lithium-Ion cell as this is the one that the teachers has given us to compare.

[jakesilove]

Hello. I need to compare dry cell to lithium cell batteries for homework but having trouble finding what is the chemical reaction of a lithium-Ion cell as this is the one that the teachers has given us to compare.

A quick google search yielded this link here. Check it out!

[bsdfjnlkasn]

What is it about HF (and F's high electronegativity) that makes it such a weak acid?
Is it because of something that happens in solution? Why is it's degree of ionisation so low if it's looking to give away it's electrons so desperately?