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AS chemistry quetion help!

Hi can someone please help me answer this question! I did some working out but getting no where :frown:

Question: Human chromosome 1 is a DNA molecule with amolar mass of 1.61 x 10¹¹ gmol^-1.

(a) Deduce the mass, in g, of a single chromosome1. Give your answer to an appropriate number of significant figures.

(b) The total mass of chromosome 1 DNA inZebulon, a human, is 19.9g. Making theapproximation that every cell in Zebulon’s body has 2 copies of chromosome 1,how many cells does his body contain?

Reply 1

Neuth

Original post by Kitty-meaw

Hi can someone please help me answer this question! I did some working out but getting no where :frown:

Can you show us your workings? :h:

We'll point out where you went wrong and show you the next correct step.

Reply 2

Kitty-meaw

Original post by Neuth

Can you show us your workings? :h:

We'll point out where you went wrong and show you the next correct step.

(a) I did 1.61x10^11 x 6.02x10^23 = 9.6922x10^34

mass= 9.6922x10^34 x 1.61x10^11= 1.5604442x10^46 g

(b) n= 19,9g/1.61x10^11
=1.236024845x10^12/2
=6.180124224x10^11 x 6.02x10^23
=3.720434783x10^35 cells

This may be completely wrong which is why i didn't show my workings, cause i'm not certain how to work it out :L

Reply 3

Ammat

Question: Human chromosome 1 is a DNA molecule with amolar mass of 1.61 x 10¹¹gmol^-1.

(a) Deduce the mass, in g, of a single chromosome1. Give your answer to an appropriate number of significant figures.
1 mole of the DNA molecules has a mass of 1.61 x 10¹¹
therefore 1 dna molecules has a mass of 1.61 x 10^{11 divided by 6.02*10 to the 23
=2.67*10-13 Think about it 1 dna molecule has to have a very small mass}

(b) The total mass of chromosome 1 DNA inZebulon, a human, is 19.9g. Making theapproximation that every cell in Zebulon’s body has 2 copies of chromosome 1,how many cells does his body contain?
1 dna molecules has a mass of 2.67*10-13g
the total mass of the dna is19.9g
19.9/2.67*10-13
=7.45*10 13 dna molecules
each cell has 2
so the number of cells= 7.45*10 13/2
=3.73*10 13 molecules :biggrin:

Reply 4

Kitty-meaw

Original post by Ammat

Question: Human chromosome 1 is a DNA molecule with amolar mass of 1.61 x 10¹¹gmol^-1.

(a) Deduce the mass, in g, of a single chromosome1. Give your answer to an appropriate number of significant figures.
1 mole of the DNA molecules has a mass of 1.61 x 10¹¹

therefore 1 dna molecules has a mass of 1.61 x 10^{11 divided by 6.02*10 to the 23}
^{=2.67*10-13 Think about it 1 dna molecule has to have a very small mass}

(b) The total mass of chromosome 1 DNA inZebulon, a human, is 19.9g. Making theapproximation that every cell in Zebulon’s body has 2 copies of chromosome 1,how many cells does his body contain?
1 dna molecules has a mass of 2.67*10-13g
the total mass of the dna is19.9g
19.9/2.67*10-13
=7.45*10 13 dna molecules
each cell has 2
so the number of cells= 7.45*10 13/2
=3.73*10 13 molecules :biggrin:

Thank you!! :smile:

but i just put 1.61 x 10^11 divided by 6.02x10^23 in the calculator and got 2.67...x10^33 not ^-13? :/