Question

Petunia needs 66.48 grams of potassium hydroxide (KOH) to run a reaction in class. How many moles of potassium hydroxide does she need? Please round your answer to two digits after the decimal point, and remember to include correct, complete units (including substance formula).

Answer 1

Petunia needs 1.18 moles of potassium hydroxide (KOH) for her reaction, calculated by dividing the mass she has (66.48 g) by the molar mass of KOH (56.11 g/mol).

Step-by-step explanation:

Petunia needs to convert 66.48 grams of potassium hydroxide (KOH) to moles. The molar mass of KOH is approximately 56.11 g/mol. To find the number of moles, you divide the mass of the compound by its molar mass:

Number of moles = mass (g) / molar mass (g/mol)

Number of moles = 66.48 g / 56.11 g/mol = 1.18 moles of KOH

Therefore, Petunia needs 1.18 moles of KOH for her reaction.

Answer 2

She needs 1.19 moles of potassium hydroxide.

Step-by-step explanation:

Being the molar mass of the elements:

• K= 39 g/mole
• O= 16 g/mole
• H= 1 g/mole

then the molar mass of potassium hydroxide is:

KOH= 39 g/mole + 16 g/mole + 1 g/mole= 56 g/mole

Being the mass of one mole of a substance, which can be an element or a compound, you can apply the following rule of three: if 56 g of KOH are present in 1 mole, 66.48 g of KOH in how many moles of the compound are they?

`moles of KOH=(66.48 grams*1 mole)/(56 grams)`

moles of KOH= 1.19

She needs 1.19 moles of potassium hydroxide.