Seven electrons. The atomic number of a element is also the amount of protons and electrons it has.
N h2o = mh20/Mh20
= 8.0g/18g/mol
=0.44 mol
therefore n O = 0.44mol
therefore n H2 = 0.88 mol
m H2 = n H2 * M H2
= 0.88 mol * 2 g/mol
=1.76 g
They are on the left side of the equation.
Assuming that the gas acts like an ideal gas, we can
calculate for the final volume using the ideal gas law:
PV = nRT
Where P = pressure, V = volume, n = number of moles, R = gas
constant, and T = temperature
Assuming that P, n, and R are constant throughout the
process, we can define another constant K:
V / T = K where
K = nR / P
Equating the initial and final states:
Vi / Ti = Vf / Tf
Substituting the given values:
11.5 cm^3 / 415 K = Vf / 200 K
Vf = 5.54 cm^3
