HSC Chemistry Question Thread

[RuiAce]

I get C as my answer, requesting confirmation please

Yep.

[bsdfjnlkasn]

I get C as my answer, requesting confirmation please

How would you go about solving this question? I'm not sure where to begin because we're not given any masses

Thank you!

[RuiAce]

How would you go about solving this question? I'm not sure where to begin because we're not given any masses

Thank you!

It says 1 kilogram of hydrazine. Which is 1000 g

[bsdfjnlkasn]

It says 1 kilogram of hydrazine. Which is 1000 g

Would we find the number of moles for N2H4 (given 1000g) and then x by 24.47?
This is the method I tried but it's obviously wrong, could you possibly start me off and I'll try again?

[RuiAce]

Would we find the number of moles for N2H4 (given 1000g) and then x by 24.47?
This is the method I tried but it's obviously wrong, could you possibly start me off and I'll try again?

You forgot to consider the equation.

After finding the number of moles of N₂H₄, we note that 2 moles of N₂H₄ produces 7 moles of 'gas'. So to get the moles of GAS produced, we must multiply by 7.2 before we consider the 24.47

[Mathew587]

Hey guys,
How the hell do we know what the products are in chemcial reaction? :/
Like in most cases, I have no idea what it would be except if its something simple like combustion. Anyone have like a basic equation sheet that would be useful for chem cos I'd love that.
Thanks peeps

[Iminschool]

Hey guys,
How the hell do we know what the products are in chemcial reaction? :/
Like in most cases, I have no idea what it would be except if its something simple like combustion. Anyone have like a basic equation sheet that would be useful for chem cos I'd love that.
Thanks peeps

I think you'll need a sheet on the rules like this one:

[Mathew587]

Yup exactly like that.
Do you happen to have one from prelim with all the equations we should know from then? I have a terrible memory btw :_

[RuiAce]

Hey guys,
How the hell do we know what the products are in chemcial reaction? :/
Like in most cases, I have no idea what it would be except if its something simple like combustion. Anyone have like a basic equation sheet that would be useful for chem cos I'd love that.
Thanks peeps

There's usually categories.

If it's oxygen with something, it's probably combustion

If it's acid with base, it's probably neutralisation

etc. You will have to provide further examples if you are confused.

[RuiAce]

Yup exactly like that.
Do you happen to have one from prelim with all the equations we should know from then? I have a terrible memory btw :_

I don't believe there are many you need to know "off by heart" in prelim.

Some things like acid + metal = salt + hydrogen might pop up.

Most of the time you need to figure it out yourself. If it's too hard they give you the equation, otherwise it should fall under a common category.

[Mathew587]

Yup I understand
I should probably just study more hehe

[anotherworld2b]

For this question. Would you explain electrostatic repulsion and attraction as well as strong nuclear force? I am not sure how much depth should be included in  this question.

I was also wondering what would be the best way to answer this question 'explain relative atomic mass?'
Could you explain it by saying the relative atomic mass of an elememt is the ration of the weighted average mass per atom of the naturally occuring form and reflexts the isotopic composition of the element?

[jakesilove]

For this question. Would you explain electrostatic repulsion and attraction as well as strong nuclear force? I am not sure how much depth should be included in  this question.

I was also wondering what would be the best way to answer this question 'explain relative atomic mass?'
Could you explain it by saying the relative atomic mass of an elememt is the ration of the weighted average mass per atom of the naturally occuring form and reflexts the isotopic composition of the element?

Yep, to both of your questions. How in depth you answer the question will depend on the marks allocated; for now, just make sure that YOU understand the answer.

[bsdfjnlkasn]

For the following outcome, do we ever need to address oxides of metals in the Acidic Environment syllabus?

Identify oxides of non-metals which act as acids and describe the conditions under which they act as acids

[RuiAce]

For the following outcome, do we ever need to address oxides of metals in the Acidic Environment syllabus?

Identify oxides of non-metals which act as acids and describe the conditions under which they act as acids

Yeah. Oxides such as sulfur dioxide and carbon dioxide are acidic, for example.

Conditions? Just write out equations showing their acidic nature.