Iridium-192 is used in cancer treatment, a small cylindrical piece of 192 Ir, 0.6 mm in diameter (0.3mm radius) and 3.5 mm long, is surgically inserted into the tumor. if the density of iridium is 22.42 g/cm3, how many iridium atoms are present in the sample?
Let us start by computing for the volume of the cylinder. V = π(r^2)*h where r and h are the radius and height of the cylinder, respectively. Let's convert all given dimensions to cm first. Radius = 0.03 cm, height is 0.35cm long.
V = π * (0.03cm)^2 * 0.35 cm = 9.896*10^-4 cm^3
Now we have the volume of 192-Ir, let's use the density provided to get it's mass, and once we have the mass let's use the molar mass to get the amount of moles. After getting the amount of moles, we use Avogadro's number to convert moles into number of atoms. See the calculation below and see if all units "cancel":
9.896*10^-4 cm^3 * (22.42 g/cm3) * (1 mole / 191.963 g) * (6.022x10^23 atoms /mole)
= 6.96 x 10^19 atoms of Ir-122 are present.
A) sulfuric acid + sodium hydroxide → sodium sulfate + water
Answer:
NH₃ and H⁺
Explanation:
The dissociation of NH₄Cl will lead to two ions , i.e. , NH⁴⁺ and Cl⁻ .
Hence , the reaction is -
NH₄Cl → NH⁴⁺ + Cl⁻
We can conclude that NH₄Cl can be formed from the ions , NH⁴⁺ and Cl⁻
Hence ,
According to the reaction ,
NH⁴⁺ + H₂O ⇆ NH₃ + H₃O⁺
Therefore ,
The reactant that will lead to the formation of NH₄Cl are - NH₃ and H⁺
