VCE Chemistry Question Thread

[Yacoubb]

Do we need to know where hydrogen bonding occurs for nitrogenous bases?

Yeah they've asked questions on it! It's the bond between H and F, O or N attached to a H. Is that correct? Clarification on this would be appreciated!

[Blondie21]

Have I converted this correctly?

[RKTR]

Have I converted this correctly?

1L = 10^-6 ML?

[Blondie21]

1L = 10^-6 ML?

Ohh damn. Thanks!!!
So is it 2.51kg?

[Blondie21]

How do I figure this out?

[lzxnl]

Do we need to know where hydrogen bonding occurs for nitrogenous bases?

Pretty sure we do .

They HAVE asked these before, but the bases are aligned in the data book in the correct orientation for H bonding

Yeah they've asked questions on it! It's the bond between H and F, O or N attached to a H. Is that correct? Clarification on this would be appreciated!

You've missed the point of the question. They weren't asking for what H bonds are. They were asking for where the H bonds were between the DNA bases. Also, that's not entirely correct. By saying 'the' bond, you imply there is only one type of bond between those atoms. Well, the bond between H and the O that is attached to a H in water is a covalent bond
Also, in proteins, the peptide C=O can form hydrogen bonds to other hydrogens because the oxygen there is quite negatively charged due to its double bond to carbon. But you have the idea.

[Blondie21]

What is the reaction from ethene to ethanol called?

My textbook says hydrolysis but I'm not sure this that this is correct

[nhmn0301]

What is the reaction from ethene to ethanol called?

My textbook says hydrolysis but I'm not sure this that this is correct

I call ethene -> ethanol (hydration) (I think apart from H20, you also need concentrated acid)
        ethanol -> ethene (dehydration)

[Yacoubb]

I call ethene -> ethanol (hydration) (I think apart from H20, you also need concentrated acid)
        ethanol -> ethene (dehydration)

It's just an addition reaction.

[Blondie21]

Why does steel corrode more rapidly when it is in contact with copper?

[lzxnl]

What is the reaction from ethene to ethanol called?

My textbook says hydrolysis but I'm not sure this that this is correct

Really? What textbook is this!?
Hydrolysis is breaking a molecule apart using water, like breaking an ester up into an alcohol and acid.

[anna.xo]

What is the reaction from ethene to ethanol called?

My textbook says hydrolysis but I'm not sure this that this is correct

It's the addition of water..so I would say hydrolysis reaction

[Yacoubb]

It's the addition of water..so I would say hydrolysis reaction

But that's not really hydrolysis.... I mean I can see how it can be because of the provision of H and OH to be added to the molecule, but there is no separation of your existing compound like if we were to hydrolysise a polypeptide or polysaccharide.

I'd personally stick to addition.

[thushan]

It's the addition of water..so I would say hydrolysis reaction

Hydration, not hydrolysis.

Hydrolysis means you're breaking a molecule into two or more 'pieces' using water as a reactant; 'hydro' means water, 'lysis' means to cut, slice, break.

Hydration means incorporating the H and O atoms in water into another molecule, where water is a reactant.

The reaction from ethene to ethanol using water is hydration.

[Sanguinne]

How do i approach questions like these:
For which of the following is the sign of the enthalpy change different from the other three?

A) CaCO3(s) ---> CaO(s) + CO2(g)
B) Na(g) -----> Na+(g) + e-
C) CO2(s) ------> CO2(g) <- I think this one is endothermic?
D) 2Cl(g) ------> Cl2(g)