Because 25% is half of 0.5 and the half life of is given as 5,715, the time it takes to reach this amount should just be double the half life: 11430 years.
However, in other cases the problem may not have easy numbers, so below is a more mathematical approach.
The half life formula is .
Solving for t gives:
Given information:
Plug in given values and solve for t.
With correct significant figures, this would be 11000 years.
Answer:
χH₂ = 0.4946
χN₂ = 0.4130
χAr = 0.0923
Explanation:
The total pressure of the mixture (P) is:
P = pH₂ + pN₂ + pAr
P = 443.0 Torr + 369.9 Torr + 82.7 Torr
P = 895.6 Torr
We can find the mole fraction of each gas (χ) using the following expression.
χi = pi / P
χH₂ = pH₂ / P = 443.0 Torr/895.6 Torr = 0.4946
χN₂ = pN₂ / P = 369.9 Torr/895.6 Torr = 0.4130
χAr = pAr / P = 82.7 Torr/895.6 Torr = 0.0923
Answer:- 5.199 moles.
Solution:- To do the conversion from number of particles to moles, we use Avogadro number. Given number of particles is divided by Avogadro number and we get the moles.
Avogadro number is . The calculations are given below:
= 5.199 moles
So, there would be 5.199 moles in particles.
Answer:
option D is correct
D. This solution is a good buffer.
Explanation:
TRIS (HOCH)CNH
if TRIS is react with HCL it will form salt
(HOCH)CNH + HCL ⇆ (HOCH)NHCL
Let the reference volume is 100
Mole of TRIS is = 100 × 0.2 = 20
Mole of HCL is = 100 × 0.1 = 10
In the reaction all of the HCL will Consumed,10 moles of the salt will form
and 10 mole of TRIS will left
hence , Final product will be salt +TRIS(9 base)
H = Pk + log (base/ acid)
8.3 + log(10/10)
8.3