Chapter 10, Problem 87QAP

When water is added to a mixture of aluminum metal and sodium hydroxide, hydrogen gas is produced. This is the reaction used in commercial drain cleaners:

$2\text{Al}\left(s\right)+6{\text{H}}_2\text{O}\left(l\right)+2{\text{OH}}^{-}\left(aq\right)\to 2\text{Al}{\left(\text{OH}\right)}_4{}^{-}\left(aq\right)+3{\text{H}}_2\left(g\right)$A sufficient amount of water is added to 49.92 g of NaOH to make 0.600 L of solution; 41.28 g of Al is added to this solution and hydrogen gas is formed.

(a) Calculate the molarity of the initial NaOH solution.

(b) How many moles of hydrogen were formed?

(c) The hydrogen was collected over water at 25°C and 758.6 mm Hg. The vapor pressure of water at this temperature is 23.8 mm Hg. What volume of hydrogen was generated?