in the reaction between sodium and water, hydrogen gas is given off and sodium hydroxide is formed. The gas is collected and there is found to be 1.8 moles of hydrogen.
a) What mass of sodium would have been used in this reaction?
b)What mass of water would have reacted with this sodium?

Question

in the reaction between sodium and water, hydrogen gas is given off and sodium hydroxide is formed. The gas is collected and there is found to be 1.8 moles of hydrogen. 
a) What mass of sodium would have been used in this reaction?
b)What mass of water would have reacted with this sodium?

anonymous · Answer

2Na+2H2O -> 2NaOH + H2

2moles Na ------> 1mole H2
so, 1.8 moles of H2 --------> ${1.8\times2\over1}=3.6$moles Na

anonymous · Answer

and 3.6moles H2O

anonymous · Answer

mass of H2O = 3.6 * molecular weight of H2O
 = 3.6* (2+16)=64.8grams