Question

# Chemical Reactions with Isotopes The coefficients in a balanced chemical equation represent the relative numbers of...

Chemical Reactions with Isotopes

The coefficients in a balanced chemical equation represent the relative numbers of each molecule or formula unit and the relative number of moles of each molecule or formula unit. In a balanced equation, the stoichiometric relationships among the substances allow us to convert between quantities of reactants and products in a reaction.

PART B QUESTION:

Consider the reaction

2H2(g)+O2(g)→2H2O(l)

What is the mass of water, H2O(l), produced when 6.10 g of O2(g) reacts with excess H2(g)?

Balanced reaction equation is:

2H2(g)+O2(g)→2H2O(l)

Stoichiometric conversion factor:

H2O to O2 is 2 mole H2O/1 mole O2

converting mass of O2 into moles by dividing with its molar mass

Molar mass of O2 = 32g/mol

Moles of 6.10g O2 = 6.10g/32g/mol = 0.191 moles O2

Moles of H2O produced can be calculated from conversion factor:

= 2 moles H2O/1 moles O2 x 0.190625 moles O2

= 0.381 moles H2O

converting it into grams by multiplying it with its molar mass:

mass of H2O = 0.381 mol x 18g/mol(molar mass of H2O)

= 6.86 g