Posted by lyne on Monday, January 5, 2009 at 4:29pm.
The element rhenium (Re) has two naturally occurring isotopes, 185Re and 187Re, with an average atomic mass of 186.207 amu. Rhenium is 62.60% 187Re, and the atomic mass of 187Re is 186.956 amu. Calculate the mass of 185Re.
am i supposed to multiply the atomic masses and the percents or something?
- chemistry - DrBob222, Monday, January 5, 2009 at 4:42pm
yes. Both multiply AND something.
0.6626*X + 0.3740(186.956) = 186.207
Make sure I have these paired right.
X stands for amu Re185. Solve for X.
- chemistry - DrBob222, Monday, January 5, 2009 at 4:49pm
You can check your answer this way.
Multiply decimal percent of amu 185 and decimal percent of amu 187, add them together and you should get 186.207.
- chemistry - lyne, Monday, January 5, 2009 at 4:59pm
shouldnt it be .626(186.956)+.374*X=186.207
- chemistry - DrBob222, Monday, January 5, 2009 at 9:12pm
yes, I don't know why I typed in 6626. It should be 0.626 and 0.374. Neither do I know why I reversed the order when I typed it in BUT I'm glad I put in the post to check my pairings. According to my notes, I have
0.374(X) + 0.626(186.956) = 186.207 which I think agrees with what you have.
My eyesight is not that great as you can tell.
- chemistry - Noksie, Sunday, April 17, 2011 at 6:37am
- chemistry - bob, Sunday, October 21, 2012 at 10:11pm
where is the 0.3740 coming from
- chemistry - NamNam, Monday, June 24, 2013 at 10:22pm
The 0.374 comes from taking 100 percent and subtracting the 62.60% from it which gives you 37.4 percent, divide by 100 to get 0.374, now multiply by x and solve as listed above.
Answer this Question
- chemistry - The element rhenium (Re) has two naturally occurring isotopes, 185Re...
- Ap Chemistry - Re has two natural occuring isotopes 185 Re and 187 Re with an ...
- Chemistry - Naturally occurring boron is 80.20% boron-11 (of atomic mass 11.01 ...
- chemistry - The element copper has naturally occuring isotopes with mass numbers...
- Chemistry - Congratulations! You have discovered a new element called Bhauzium (...
- Chemistry - Element X consists of two major isotopes with the following percent ...
- Chemistry - Four isotopes of Lead occur naturally: 204Pb (mass = 203.973037 amu...
- Chemistry - Boron has only two naturally occurring isotopes. The mass of boron-...
- Chemistry - An element consists of two isotopes of mass 36.4681 and 43.59612 amu...
- Chemistry - The element europium exists in nature as two isotopes: 151^Eu has a ...