So the molarity equation is moles of solute/liters of solution. so i’m pretty sure the answer should be 0.63/0.70= .9
The alkaline earth metals (the second group) because their ion charge is +2
Answer:
B
Explanation:
Molarity = 0.010M
Volume = 2.5L
Applying mole-concept,
0.010mole = 1L
X mole = 2.5L
X = (0.010 × 2.5) / 1
X = 0.025moles
0.025moles is present in 2.5L of NaOH solution.
Molar mass of NaOH = (23 + 16 + 1) = 40g/mol
Number of moles = mass / molar mass
Mass = number of moles × molar mass
Mass = 0.025 × 40
Mass = 1g
1g is present in 2.5L of NaOH solution
Answer:
20619.4793 years
Explanation:
The half life of carbon-14 = 5730 years
The formula for the half life for a first order kinetic reaction is:
Where,
is the half life
k is the rate constant.
Thus rate constant is:
5730 years=ln(2)/k
k = 1.21×10⁻⁴ years ⁻¹
Using integrated rate law as:
Where,
is the concentration at time t
is the initial concentration
Given that the final concentration contains 8.25 % of the original quantity which means that:
So,
ln(.0825)= -1.21×10⁻⁴×t
<u>
t = 20619.4793 years</u>
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On Earth it is relatively rare—5.2 ppm by volume in the atmosphere. Most terrestrial helium<span> present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of </span>helium<span>-4 nuclei.</span>
