Answer:
half-life = 3.8 days
total time of decay = 15.2 days
initial amount = 100. g
number of half-lives past: 15.2/3.8 = 4 half-lives
4 half-lives = 1/16 remains
100. g x 1/16 = 6.25 g
The half-life of carbon-14 is about 5730 years
Answer:
Δ S = 93.8 J/mol-K
Explanation:
Given,
Boiling point of chloroform = 61.7 °C
= 273 + 61.7 = 334.7 K.
Enthalapy of vapourization = 31.4 kJ/mol.
Using Gibbs free energy equation
Δ G = Δ H - T (ΔS)
at equilibrium (when the liquid is boiling), Δ G = 0
so, 0 = ΔH - T (Δ S)
T (Δ S) = Δ H
and ΔS = ΔH / T
Δ S = (31400 J/mol.) / 334.7 K
Δ S = 93.8 J/mol-K
Sodium. 11
Carbon. 12
Hydrogen 1
Oxygen 2
Fluuorine. 14
Boron. 5
Lithium. 6
Helium 3
Phosphorus 15
Sulfur 6
Answer: 8.691 mols of CO₂
Explanation:
To find the number of moles in a given grams, you want to use the molar mass.
Let's first find the molar mass of CO₂.
Carbon's molar mass is 12.011 g/mol
Oxygen's molar mass is 15.999 g/mol
To find molar mass of CO₂, we want to add up the molar mass of carbon and oxygen. Remember, there are 2 Oxygens so we need to mulitply that by 2.
12.011+2(15.999)=44.009 g/mol
Now that we have molar mass, we can convert 382.5 g to mols.
There are about 8.691 mols of CO₂.