Answer:
35Cl ⇒ 34.968853 amu has an abundance of 30.05%
Explanation:
The molar mass of chlorine, (which is the average of all its naturally stable isotope masses), is 36.36575 amu.
There are 2 naturally stable isotopes, this means together they have an abundance of 100%
The isotopes are:
35Cl ⇒ 34.968853 amu has an abundance of X %
37Cl ⇒ 36.965903 amu has an abundance of Y %
X + Y = 100% OR X = 100% - Y
36.36575 = 34.968853X + 36.965903Y
36.36575 = 34.968853(1-Y) + 36.936.96590365903Y
36.36575 = 34.968853 -34.968853Y + 36.965903Y
1.396897 = 1.99705Y
Y = 0.699 = 69.95%
X = 100-69.9 = 30.05%
To control, we can plug in the following equation:
34.968853 * 0.3005 + 36.965903 * 0.6995 = 36.3658
This means
37Cl ⇒ 36.965903 amu has an abundance of 69.95 %
35Cl ⇒ 34.968853 amu has an abundance of 30.05%
Answer:
The order will be:
CCH > CHCH₂ > CH₂CH₃> CH₃
Explanation:
According to Cahn-Ingold-Prelog system we rank the groups based on the atomic number of directly attached atom with the chiral carbon.
For example: between C and H, we rank Carbon first.
If the same atoms are attached for different groups then we prioritized based on the second element with highest atomic number.
For example:
Among CH₃ and C₂H₅, the priority will be given to C₂H₅.
If an atom is double or triple bonded to the directly attached atom then each pi bond is considered to be a new atom.
Hence CH=CH₂ means, that there are two carbons attached to CH carbon.
So the order based on above selection rules will be:
CCH > CHCH₂ > CH₂CH₃> CH₃
Each year over 100,000 new organic compounds are produce
<span>In 1669 German merchant and amateur alchemist Hennig Brand attempted to created a Philosopher’s Stone; an object that supposedly could turn metals into pure gold. He heated residues from boiled urine, and a liquid dropped out and burst into flames. This was the first discovery of phosphorus.
In 1680 Robert Boyle also discovered phosphorus, and it became public.
In 1809 at least 47 elements were discovered, and scientists began to see patterns in the characteristics.
In 1863 English chemist John Newlands divided the then discovered 56 elements into 11 groups, based on characteristics.
In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.
In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discovered radium and polonium. They discovered that beta particles were negatively charged.
In 1894 Sir William Ramsay and Lord Rayleigh discovered the noble gases, which were added to the periodic table as group 0.In 1897 English physicist J. J. Thomson first discovered electrons; small negatively charged particles in an atom. John Townsend and Robert Millikan determined their exact charge and mass.
In 1900 Bequerel discovered that electrons and beta particles as identified by the Curies are the same thing.
In 1903 Rutherford announced that radioactivity is caused by the breakdown of atoms.
In 1911 Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.
In 1913 Bohr discovered that electrons move around a nucleus in discrete energy called orbitals. Radiation is emitted during movement from one orbital to another.
In 1914 Rutherford first identified protons in the atomic nucleus. He also transmutated a nitrogen atom into an oxygen atom for the first time. English physicist Henry Moseley provided atomic numbers, based on the number of electrons in an atom, rather than based on atomic mass.
In 1932 James Chadwick first discovered neutrons, and isotopes were identified. This was the complete basis for the periodic table. In that same year Englishman Cockroft and the Irishman Walton first split an atom by bombarding lithium in a particle accelerator, changing it to two helium nuclei.
In 1945 Glenn Seaborg identified lanthanides and actinides (atomic number >92), which are usually placed below the periodic table.</span>
Answer:
Percent yield: 78.2%
Explanation:
Based on the reaction:
4Al + 3O₂ → 2Al₂O₃
<em>4 moles of Al produce 2 moles of Al₂O₃</em>
<em />
To find percent yield we need to find theoretical yield (Assuming a yield of 100%) and using:
(Actual yield (6.8g) / Theoretical yield) × 100
Moles of 4.6g of Al (Molar mass: 26.98g/mol) are:
4.6g Al × (1mol / 26.98g) = 0.1705 moles of Al.
As 4 moles of Al produce 2 moles of Al₂O₃, theoretical moles of Al₂O₃ obtained from 0.1705 moles of Al are:
0.17505 moles Al × (2 moles Al₂O₃ / 4 moles Al) = <em>0.0852 moles of Al₂O₃</em>,
In grams (Molar mass Al₂O₃ = 101.96g/mol):
0.0852 moles of Al₂O₃ × (101.96g / mol) =
<h3>8.7g of Al₂O₃ can be produced (Theoretical yield)</h3>
Thus, Percent yield is:
(6.8g / 8.7g) × 100 =
<h3>
78.2% </h3>
