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Chemistry Homework Help => General Chemistry => Topic started by: T.O.theYankee on September 22, 2010, 11:01:27 PM

Title: Reactions and Limiting Reactents and Excess Reactants
Post by: T.O.theYankee on September 22, 2010, 11:01:27 PM
Calcium oxide reacts with water in a combination reaction to producecalcium hydroxide:

Ca (solid) + H2O (liquid) ----> Ca(OH)2 (solid)

A 4.50-g sample of CaO is reacted with 4.34 g of H2O. How many grams of water remains after completion of the reaction?
Title: Re: Reactions and Limiting Reactents and Excess Reactants
Post by: T.O.theYankee on September 22, 2010, 11:10:45 PM
i got the answer to be a out 2.9-g of H2O remaining any one else know if thats right?
Title: Re: Reactions and Limiting Reactents and Excess Reactants
Post by: uma on September 23, 2010, 09:41:00 AM

CaO (solid) + H2O (liquid) ----> Ca(OH)2 (solid)

molar mass of CaO = 40+16 = 56g
molar mass of H2O = 18 g
amount of water reacting with 4.50 g of CaO =4. 50g CaO  X 18 g H2O / 56 gCaO =1.446 g
amount of water left unreacted = 4.34g - 1.446g =2.89g