Question

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide : CaO + H2O >> Ca(OH)2 A 3.50 g sample of CaO is reacted with 3.38 g of H2O
Calculate how many moles of CaO and H2O . Identify the limiting reagent . How many grams of water remain after completion of reaction ?

Answer 1

Answer on Question #55235 – Chemistry – Other

Question:

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:

$$\mathrm{CaO} + \mathrm{H_2O} \gg \mathrm{Ca(OH)_2}$$

A 3.50 g sample of CaO is reacted with 3.38 g of H₂O.

Calculate how many moles of CaO and H₂O identify the limiting reagent. How many grams of water remain after completion of reaction?

Answer:

$$v = \frac{m}{M}$$ $$v(\mathrm{CaO}) = v(\mathrm{H_2O}) = v(\mathrm{Ca(OH)_2})$$ $$M(\mathrm{CaO}) = 56 \text{ g/mol}$$ $$M(\mathrm{H_2O}) = 18 \text{ g/mol}$$ $$M(\mathrm{Ca(OH)_2}) = 74 \text{ g/mol}$$ $$v(\mathrm{CaO}) = \frac{3.50}{56.07} = 0.06 \text{ moles}$$ $$v(\mathrm{H_2O}) = \frac{3.38}{18.01} = 0.19 \text{ moles}$$

The limiting agent in this reaction is CaO. Its amount is less, so that it is used faster.

After the reaction the amount of water left is:

$$v(\mathrm{H_2O})_{\text{left}} = 0.19 - 0.06 = 0.13 \text{ moles}$$

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