H2 (g) is made when 8.5 grams of Li is placed in water. The reaction also creates Lithium Hydroxide. Li + H2O --> LiOH + H2 How much H2 (g) is made? (the (g) means gas!)
Here is an example problem. Just follow the steps.
http://www.jiskha.com/science/chemistry/stoichiometry.html
i know how to do it but i didn't get any of the answer choices
To determine the amount of H2 (g) produced in the reaction, we can use the concept of stoichiometry and the given mass of Li.
The balanced chemical equation is:
2Li + 2H2O → 2LiOH + H2
From the equation, we can see that 2 moles of Li will produce 1 mole of H2.
First, we need to calculate the number of moles of Li by dividing the given mass of Li (8.5 grams) by its molar mass. The molar mass of Li is approximately 6.94 g/mol.
Moles of Li = 8.5 g / 6.94 g/mol ≈ 1.22 mol
Since 2 moles of Li produce 1 mole of H2, we can conclude that for every 1.22 moles of Li, we will have 0.61 moles of H2.
Finally, to convert moles of H2 to grams, we can multiply the number of moles by the molar mass of H2, which is approximately 2.02 g/mol.
Mass of H2 = 0.61 mol × 2.02 g/mol ≈ 1.23 g
Therefore, approximately 1.23 grams of H2 (g) will be produced in the reaction.