Under certain conditions, the substances zinc oxide and water combine to form zinc hydroxide. If 30.1 grams of zinc oxide and 6.7 grams of water combine to form zinc hydroxide, how many grams of zinc hydroxide must form

36.8g of Zinc hydroxide

Explanation:

Based on the reaction:

ZnO + H₂O → Zn (OH) ₂

Where 1 mole of zinc oxide reacts with 1 mole of water to produce 1 mole of zinc hydroxide.

Moles of 30.1g of ZnO (FW = 81.38g/mol) are:

30.1g ZnO ₓ (1mol / 81.38g) = 0.370 moles of ZnO

And moles of 6.7g of H₂O (FW = 18.01g/mol) are:

6.7g H₂O ₓ (1mol / 18.01g) = 0.372 moles of H₂O

As 1 mole of ZnO reacts per mole of H₂O, limiting reactant is ZnO because has a less number of moles than water.

Thus, moles of Zn (OH) ₂ produced are 0.370 moles.

As Molar mass of Zinc hydroxide is 99.424 g/mol, there are formed:

0.370 moles Zn (OH) ₂ ₓ (99.424g / mol) =

36.8g of Zinc hydroxide