How many moles of sodium hydroxide are produced when 0.155 mole of sodium reacts with excess water?

2Na + 2H2O ==> 2NaOH + H2

You have 0.155 mol Na.
The equation tells you that 1 mol H2 is produced for each 2 mols Na.

To determine how many moles of sodium hydroxide are produced, we need to know the balanced chemical equation for the reaction between sodium and water.

The balanced chemical equation for the reaction between sodium and water is:

2 Na + 2 H2O -> 2 NaOH + H2

According to the equation, 2 moles of sodium react with 2 moles of water to produce 2 moles of sodium hydroxide and 1 mole of hydrogen gas.

Since you are given 0.155 moles of sodium, you can conclude that the reaction will produce the same number of moles of sodium hydroxide.

Therefore, 0.155 moles of sodium will produce 0.155 moles of sodium hydroxide.