Answer:
18
Explanation:
Element Symbol no of Atoms
Copper Cu 3
Sulfur S 3
Oxygen O 12
18 = total
If we abbreviate the formula for nicotine as Nic, then the equations for two different equilibria of Nic in water are
Nic + H2O ---> NicH+ + OH-
NicH+ + H2O ---> NicH2 2+ + OH-
We can write the Kb1 expression for the first equation as
Kb1 = 1.0×10^-6 = [NicH+][OH-] / [Nic]
1.0×10^-6 = x^2 / 1.85×10^-3 - x
Approximating that x is negligible compared to 1.85×10^-3 simplifies the equation to
1.0×10^-6 = x^2 / 1.85×10^-3
x = 0.0000430
x = [OH-] = 4.30×10^-5 M
From the Kb2 expression
Kb2 = 1.3×10-11 = [NicH2 2+][OH-] / [NicH+]
1.1×10^-10 = x^2 / 4.30×10^-5 - x
Approximating that x is negligible compared to 4.30×10^-5 simplifies the equation to
1.1×10^-10 = x^2 / 4.30×10^-5
x = [OH-] = 6.88×10^-8
The concentration [OH-] can be computed as
[OH-] = 4.30×10^-5 M + 6.88×10^-8 M = 4.30×10^-5 M
This shows that the second equilibrium has a negligible effect on the pH.
We can now calculate for pH:
pOH = -log [OH-] = -log (4.30×10^-5 M) = 4.37
pH = 14 - pOH = 14 - 4.37 = 9.63
I would say that it sounds like you are an alchemist as during the 1500's at least they tried to turn base metals like Pb or lead into Au or gold. While this is not possible, their experiments gave rise to the science and techniques of metallurgy and assaying as confirmed by the great first mine geologist, Georgius Agricola in the 1500's,
Answer:
Mass =41.36 g
Explanation:
Given data:
Mass of CH₄ = 15 g
Mass of O₂ = 114 g
Mass of CO₂ produced = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of CH₄:
Number of moles = mass/ molar mass
Number of moles = 15 g /16 g/mol
Number of moles = 0.94 mol
Number of moles of O₂:
Number of moles = mass/ molar mass
Number of moles = 114 g /32 g/mol
Number of moles = 3.6 mol
Now we will compare the moles of CO₂ with both reactant.
O₂ : CO₂
2 : 1
3.6 : 1/2×3.6= 1.8 mol
CH₄ : CO₂
1 : 1
0.94 : 0.94
Number of moles of CO₂ produced by CH₄ are less so it will limiting reactant.
Mass of CO₂:
Mass = number of moles × molar mass
Mass = 0.94 mol × 44 g/mol
Mass =41.36 g