Serotonin is a molecule composed of 10 carbon atoms (black), 12 hydrogen atoms (white), 2 nitrogen atoms (blue), and 1 oxygen atom (red).
These events are actually sorted right, according to the time they occurred.
1. Democritus proposes the existence of atoms - this happened in the 5th century BC
2. Dalton's atomic theory - it was first presented in 1803
3. J.J. Thomson discovers the electron - happened in 1897
4. Rutherford's gold foil experiment - somewhere between 1908 and 1913
5. Bohr model - it was introduced in 1913
6. Schrodinger's wave - the equation was published in 1925
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
