The threshold frequency of Cesium is 5.2 x 10^14 Hz.
To find the frequency of yellow light, we use the equation: speed of light = wavelength x frequency 3 x 10^8 = 5.8 x 10^-17 x frequency frequency = 5.17 x 10^24
This is higher than the threshold frequency of Cesium, thus, electrons will be emitted.
2.5 mole O2 should react (2 * 2.5) = 5.0 mole H2 but there is 6.0 mole H2. H2 remain in excess. O2 is the limiting reactant. mole of H2O formed = 2 * 2.5 = 5.0 mole.
