<span>Ans :
The chemical formula for aluminum sulfate is Alâ‚‚(SOâ‚„)â‚
6.00 mol Alâ‚‚(SOâ‚„)â‚
Al: 6.00 mol Alâ‚‚(SOâ‚„)â‚ x (2 mol Al / 1 mol Alâ‚‚(SOâ‚„)â‚ ) = 12.00 mol Al
S: 6.00 mol Alâ‚‚(SOâ‚„)â‚ x (3 mol S / 1 mol Alâ‚‚(SOâ‚„)â‚ ) = 18.00 mol S
O: 6.00 mol Alâ‚‚(SOâ‚„)â‚ x (12 mol O / 1 mol Alâ‚‚(SOâ‚„)â‚ ) = 72.00 mol O</span>
Using the ideal gas law equation, we can find the number of H₂ moles produced.
PV = nRT
Where P - pressure - 0.811 atm x 101 325 Pa/atm = 82 175 Pa
V - volume - 58.0 x 10⁻³ m³
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 32 °C + 273 = 305 K
substituting these values in the equation,
82 175 Pa x 58.0 x 10⁻³ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 305 K
n = 1.88 mol
The balanced equation for the reaction is as follows;
CaH₂(s) + 2H₂O(l) --> Ca(OH)₂(aq) + 2H₂(g)
stoichiometry of CaH₂ to H₂ is 1:2
When 1.88 mol of H₂ is formed , number of CaH₂ moles reacted = 1.88/2 mol
therefore number of CaH₂ moles reacted = 0.94 mol
Mass of CaH₂ reacted - 0.94 mol x 42 g/mol = 39.48 g of CaH₂ are needed
Both bc your buying the product and a service of them installing it
For radioactive decay, we can relate current amount, initial amount, decay constant and time using:
N = No x exp(-λt)
Half-life = ln(2)/λ
λ = ln(2) / 5730
N/No = 80% = 0.8
0.8 = exp( -ln(2)/5730 x t)
t = 1844 years
