Radioactive material obeys 1st order decay kinetics,
For 1st order reaction, we have
k =

where, k = rate constant of reaction
Given: Initial conc. 100, Final conc. = 6.25, t = 18.9 hours
∴ k =

= 0.1467 hours^(-1)
Now, for 1st order reactions: half life =

= 4.723 hours.
Answer:
Explanation:
From the information given:
Mass of carbon tetrachloride = 5 kg
Pressure = 1 bar
The given density for carbon tetrachloride = 1590 kg/m³
The specific heat of carbon tetrachloride = 0.84 kJ/kg K
From the composition, the initial volume of carbon tetrachloride will be:
= 0.0031 m³
Suppose
is independent of temperature while pressure is constant;
Then:
The change in volume can be expressed as:





However; the workdone = -PdV

W = - 7.6 J
The heat energy Q = Δ h


Q = 84 kJ
The internal energy is calculated by using the 1st law of thermodynamics; which can be expressed as;
ΔU = ΔQ + W
ΔU = 84 kJ + ( -7.6 × 10⁻³ kJ)
ΔU = 83.992 kJ
Carbonic anhydrase speeds up<span> the transfer of carbon dioxide from cells to the blood.
Hope this work cuz</span>
They're only found in the nucleus and play an important role in keeping the atom stable because they carry a negative charge to counteract the proton's positive charge.