Random Question Thread.

[d0minicz]

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[hyperblade01]

4.65g of metal X formed an oxide with an emperical formula of XO3 ,and a mass of 8.94g. What is the relative atomic mass of the metal X?
thanks
edit: i mean ; do we just assume 1:1 ratio? need help on that

Really rough explanation:

Mass of XO3 - Mass of X = Mass of O3
8.94 - 4.65 = 4.29

Using this, you find the % mass of O3 in XO3

4.29/8.94 x 100 = 48%

O3 has a mass of 48g mol-1 so this means 48% of XO3 has a mass of 48g mol-1. As X makes up the other 52% of XO3, it will have a mass of 52g mol-1

[chem-nerd]

m(O) = 8.94 - 4.65g
calculate n(O)
n(X) = 1/3n(O)
calculate Ar(X)

[d0minicz]

When asparagine is at pH 2, do both of the amino groups gain a hydrogen? so theres two + ends

[cns1511]

When asparagine is at pH 2, do both of the amino groups gain a hydrogen? so theres two + ends

From what I've been told they do. So it will have an overall +2 charge.

(correct me if I'm wrong:P)

[d0minicz]

thanks

I need an explanation about the hydrolysis of nucleotides
say if a segment of DNA contained 40 nucleotides in total , how many waters would be required to hydrolyse?
thanks

[cns1511]

thanks

I need an explanation about the hydrolysis of nucleotides
say if a segment of DNA contained 40 nucleotides in total , how many waters would be required to hydrolyse?
thanks

You would need one less than the number of nucleotides, so 39.

[d0minicz]

dont you have to take into account the phosphate and the sugar-base too

[hyperblade01]

A nucleotide is the sugar, phosphate group and base - it's one collective thing

[TrueTears]

thanks

I need an explanation about the hydrolysis of nucleotides
say if a segment of DNA contained 40 nucleotides in total , how many waters would be required to hydrolyse?
thanks

If the question said "...to totally break down the nucleotide" then yes, you'd need to talk into consideration the phosphate and base groups.

[d0minicz]

Can someone show me the workings to do that pls ?

[cns1511]

For entire nucleotides. It's just one water less then your amount of nucleotides.
For the whole thing to be broken into it's components you would need the 39 waters (for breaking each nucleotide into single units) then 2 waters per nucleotide. So.. 39 + (2x 40) = 119.
Is this right?

[d0minicz]

Sorry i meant to say COMPLETELY hydrolyse (including phosphodiester bond and such)
dunno how to do these

[TrueTears]

For entire nucleotides. It's just one water less then your amount of nucleotides.
For the whole thing to be broken into it's components you would need the 39 waters (for breaking each nucleotide into single units) then 2 waters per nucleotide. So.. 39 + (2x 40) = 119.
Is this right?

Yes, that's right

[d0minicz]

so that 'two water molecules per nucleotide' accounts for the base/phosphate too yeap