<u>Answer:</u> The half life of the reaction is 1190.7 seconds
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:
where,
k = rate constant of the reaction = 
= half life of the reaction = ?
Putting values in above equation, we get:
Hence, the half life of the reaction is 1190.7 seconds
Answer:
The final and initial concentration of the acid and it's conjugate base are approximately equal, that is we use the weak acid approximation.
Explanation:
The Henderson-Hasselbalch is used to calculate the pH of a buffer solution. It depends on the weak acid approximation.
Since the weak acid ionizes only to a small extent, then we can say that [HA] ≈ [HA]i
Where [HA] = final concentration of the acid and [HA]i = initial concentration of the acid.
It also follows that [A^-] ≈ [A^-]i where [A^-] and[A^-]i refer to final and initial concentrations of the conjugate base hence the answer above.
Answer:
The new element will be thorium-226 (²²⁶Th).
Explanation:
The beta decay is given by:
Where:
A: is the mass number
Z: is the number of protons
β⁻: is a beta particle = electron
: is an antineutrino
The neutral atom has 88 electrons, so:
Hence the element is radium (Ra), it has A = 226.
If Ra undergoes 2 rounds of beta minus decay, we have:
Therefore, if a neutral atom with 88 electrons undergoes 2 rounds of beta minus decay the new element will be thorium-226 (²²⁶Th).
I hope it helps you!
Basis: 1 L of the substance.
(1.202 g/mL) x (1000 mL) = 1202 g
mass solute = (1202 g) x 0.2 = 240.2 g
mass solvent = 1202 g x 0.8 = 961.6 g
moles KI = (240.2 g) x (1 mole / 166 g) = 1.45 moles
moles water = (961.6 g) x (1 mole / 18 g) = 53.42 moles
1. Molality = moles solute / kg solvent
= 1.45 moles / 0.9616 kg = 1.5 m
2. Molarity = moles solute / L solution
= 1.45 moles / 1 L solution = 1.45 M
3. molar mass = mole solute / total moles
= 1.45 moles / (1.45 moles + 53.42 moles) = 0.0264
