Name: Importance of Chemistry in Everyday Life
Uploaded: 2019-07-19
Duration: 3 min 4 s
Description: Chemicals play a very important role in our daily life and several biological processes. They also find application in the agricultural, textile and medicina...

Question

The average atomic mass of copper is

63.546 amu

. Natural copper consists of two isotopes:

{}^{63}{Cu}

and

{}^{65}{Cu}

. Their natural abundances are

69.09 %

and

30.91 %

respectively. If the mass of

{}^{63}{Cu}

isotope is

62.9298 amu

, what is the mass of

{}^{65}{Cu}

isotope?

Accepted Answer

The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as Dalton, D). The atomic mass is a weighted average of all the isotopes of that element, in which the mass is multiplied by the abundance of that particular isotope.

Average atomic mass $=$ [(Abundance $\times$ atomic mass) of ${}^{63}{Cu}$ $+$ (Abundance $\times$ atomic mass) of $69.09 %$ ]

$63.546 amu = [(\frac{69.09}{100} \times 62.9298) + (\frac{30.91}{100} \times (x))] . 63.546 amu = \frac{1}{100} [(69.09 \times 62.9298) + 30.91 x] . (6354.600 - 4347.819) amu = 30.91 x . x = \frac{2006.781}{30.91} = 64.9233 amu .$

The average atomic mass of copper is $63.546 amu$ . Natural copper consists of two isotopes: ${}^{63}{Cu}$ and ${}^{65}{Cu}$ . Their natural abundances are $69.09 %$ and $30.91 %$ respectively. If the mass of ${}^{63}{Cu}$ isotope is $62.9298 amu$ , what is the mass of ${}^{65}{Cu}$ isotope?

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The average atomic mass of copper is 63.546 amu. Natural copper consists of two isotopes: Cu63 and Cu65. Their natural abundances are 69.09 % and 30.91 % respectively. If the mass of Cu63 isotope is 62.9298 amu, what is the mass of Cu65 isotope?