Question

Supposeof an alkaline earth metal reacts withof water to produceof hydrogen gas at and . Identify the metal and determine of the solution.

Short answer

The metal is calcium and of the solution is 12.7.

Step-by-step solution

Definition of Molar mass

Alkaline earth metals react with water, producing hydrogen gas:

The molar mass of an unknown alkali metal can be calculated from the mass given in the exercise and the moles of metal that reacted with water. Molar mass

of Calculation 

We assume that all the metal reacted with the water.

Therefore, from the ratio of the moles of hydrogen gas and the moles of alkali metal, we can determine the moles of the alkali metal.

The moles of hydrogen gas that is produced can be calculated from the equation for ideal gas law.

Calculation of Molar mass

Molar

Molar mass

Molar mass

The calculated molar mass matches the molar ma

Calculation of  

is calculated according to the equation shown below.

The

ion concentration can be calculated from the ion concentration using the equation for the dissociation of water. Moles can be calculated from the ratio of moles of to moles of . ss