Thallium-201 has a half-life 73 hours. If 4.0 mg of thallium-201 disintegrates over a period of 5.0 °, how many milligrams of th
1 answer:
<u>Given:</u>
Half life of Thallium-201 (T1/2)= 73 hrs
Initial amount of thallium (A₀) = 4.0 mg
Disintegration Time period (t) = 5.0 hrs
<u>To determine:</u>
Amount of thallium remaining, A
<u>Explanation:</u>
The radioactive half-life (T1/2) can be related to the amounts of the radio active element through the relation:
A =
A = 4.0 * = 3.815 mg
Ans: Amount of thallium-201 remaining is 3.815 mg
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<u>Answer:</u> The ionic compound formed is magnesium chloride having formula
<u>Explanation:</u>
Ionic compound is defined as the compound which is formed by complete transfer of electrons from one atom to another atom.
The atom which looses the electron is known as electropositive atom and the atom which gains the electron is known as electronegative atom. This bond is usually formed between a metal and a non-metal.
Magnesium is the 12th element of the periodic table having electronic configuration of
This element will loose 2 electrons to form ion
Chlorine is the 17th element of the periodic table having electronic configuration of
This element will gain 1 electron to form ion
So, for every 1 atom of magnesium, 2 atoms of chlorine are required. Thus, the chemical formula becomes
Hence, the ionic compound formed is magnesium chloride having formula
Answer:
A) 2.69 M
B) 0.059
Explanation:
A) We have:
33.8% solute by mass= 33.8 g solute/100 g solution
molarity = mol solute/ 1 L solution
molarity= x
x
x
molarity= 2.69 mol solute/L solution = 2.69 M
B) We know that there are 33.8 g of solute in 100 g of solution.
As the total solution is compounded by solute+solvent (in this case, solvent is water), the mass of water is the difference between the mass of the total solution and the mass of solute:
mass of water= 100 g - 33.8 g = 66.2 g
Now, we calculate the number of mol of both solute and water:
mol solute= 33.8 g solute x = 0.232 mol
mol H20= 66.2 g H₂O x
Finally, the mol fraction of solute (Xsolute) is calculated as follows:
Xsolute=
Xsolute= 0.059