What is the number of moles hydrogen produced when 6 moles of sodium are used? 2na + 2h2o -> 2naoh + h2

The  number of moles hydrogen produced when 6 moles of sodium are used is calculated  as below

2Na + 2H2O = 2NaOH  +H2

by use of mole ratio between Na to H2 which is 2:1 the moles of H2 is therefore

= 6 x1/2 = 3  moles of H2

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water