Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h
Answer:
1-Fluoro-4-nitrobenzene
Step-by-step explanation:
Step 1. Identify the substituents on the ring,
The groups are <em>fluoro</em> and <em>nitro</em>. They have no priority as functional groups, so the base name is <em>benzene</em>.
Step 2. Identify their relative priorities.
F and NO₂ have no functional group priority, so we list them in alphabetical order. F has <em>alphabetical priority </em>over NO₂. The name becomes <em>fluoronitrobenzene</em>.
Step 3. Number the atoms of the ring.
The C atom bearing the F is <em>C1.</em> Count around the ring, and the NO₂ group is on <em>C4</em>.
Step 4. Name the compound.
Insert the locating numbers <em>immediately in front</em> of the substituents. Use <em>hyphens</em> to join letters to numbers.
The name becomes 1-fluoro-4-nitrobenzene.
Let's assume that change of pressure of PCl₅ is X
According to the ICE table,
PCl₅(g) ⇄ PCl₃(g) + Cl₂(g)
Initial Pressure 0.123 - -
Change -X +X +X
Equilibrium 0.123 - X X X
Kp = Ppcl₃(g) x Pcl₂(g) / Ppcl₅(g)
by substitution,
0.0121 = X × X / (0.123 - X)
0.0121 × (0.123 - X) = X²
1.4883 × 10⁻³ - 0.0121X = X²
X² + 0.0121X - 1.4883 × 10⁻³ = 0
X₁ = 0.03735 or X₂ = -0.03865
X cannot be a negative value since X is a pressure.
Hence,
X = 0.03735 atm
Hence, partial pressure of PCl₃ is 0.03735 atm
