When equilibrium is reached after both reactants are placed in an empty vessel at standard conditions, partial pressures are equal?

Not necessarily, the equilibrium does not necessarily mean that the partial pressures are equal-- to explain this, you could look up the equilibrium constant of partial pressures. They are ratios, and not just equal partial pressures!

Carbon-14 has a half-life of 5,730 years and most igneous rock is older than that.

Leaves specifically the gas exchange between plants and the environment. while plants undergo photosynthesis, they also partake in cellular respiration. respiration is the process that happens in the leaves of plants.