Friday, November 20, 2009

Chemistry moles?

1.how many moles of water can be made from 4 moles of oxygen gas and 16 moles of hydrogen gas? what is the limiting reagent?





2. what is the mass of water produced from the reaction of 24g of H2 and 160 g of O2. what is the limiting reagent?

Chemistry moles?
First you need to write a balanced chemical equation for water.





2H2 +O2 --%26gt; 2H2O





Then, using the coefficients from this equation, you can determin the limiting reagent. 4 moles of oxygen would form 8 moles of water. 16 moles of hydrogen would make 16 moles of water. Therefore, oxygen is the limiting reagent, and only 8 moles of water will form.





In order to answer question 2, you need to convert grams to moles. 24 grams of H2 is the equivalent of 12 moles of H2, since 24 g H2 x (1 mol H2/2 g H2) = 12 moles H2.





160 grams of O2 is the equivalent of 5 moles of oxygen. Ten moles of water are then expected to form from these 5 moles of O2.


You can convert 10 moles of H2O to mass by multiplying by molar mass-- 10 moles H2O x (18 g H2O/1 mol) = 180 g water.

night jasmine

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