Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:
A 2.00-g sample of is reacted with 1.93 g of . How many grams of water remain after the reaction is complete?
0.0714
1.29
0.00
1.04
0.00396
The answer is actually 1.29 I just did it in Mastering Chemistry and got it right
Please re-read your question and make corrections as needed. You omitted some words.
To determine the grams of water remaining after the reaction is complete, we need to calculate the amount of water that reacts with calcium oxide and subtract it from the initial amount of water.
First, let's calculate the number of moles of calcium oxide (CaO) and water (H2O) using their molar masses:
Molar mass of CaO = 56.08 g/mol
Molar mass of H2O = 18.02 g/mol
Number of moles of CaO = 2.00 g / 56.08 g/mol = 0.0356 mol
Number of moles of H2O = 1.93 g / 18.02 g/mol = 0.107 mol
The balanced chemical equation for the reaction is:
CaO + H2O → Ca(OH)2
From the equation, we can see that 1 mol of CaO reacts with 1 mol of water to form 1 mol of calcium hydroxide (Ca(OH)2).
Since the reaction is a combination reaction, all the CaO will react with the water completely. Therefore, the amount of CaO reacted will be equal to the amount of Ca(OH)2 formed.
Number of moles of Ca(OH)2 formed = Number of moles of CaO reacted = 0.0356 mol
Now, let's calculate the amount of water that reacts with the CaO:
Molar ratio of CaO to H2O = 1:1
Number of moles of H2O reacted = 0.0356 mol
Since the reaction consumes the same amount of water as CaO, the remaining amount of water after the reaction is complete will be given by:
Remaining moles of H2O = Initial moles of H2O - Moles of H2O reacted
= 0.107 mol - 0.0356 mol
= 0.0714 mol
Finally, let's convert the moles of water remaining to grams:
Mass of water remaining = Moles of water remaining x Molar mass of H2O
= 0.0714 mol x 18.02 g/mol
≈ 1.29 g
Therefore, the correct answer is 1.29 g.