Question

Molarity of 74.6 g C₂H6O in 2.36 L of solution

Answer 1

0.686 M

Step-by-step explanation:

To find the molarity of C₂H₆O, you need to (1) convert grams to moles (using the molar mass of C₂H₆O) and then (2) calculate the molarity (using the molarity ratio). The final answer should have 3 sig figs like the given values.

(Step 1)

Atomic Mass (C): 12.011 g/mol

Atomic Mass (H): 1.008 g/mol

Atomic Mass (O): 15.999 g/mol

Molar Mass (C₂H₆O): 2(12.011 g/mol) + 6(1.008 g/mol) + 15.999 g/mol

Molar Mass (C₂H₆O): 46.069 g/mol

74.6 g C₂H₆O 1 mole
------------------------- x -------------------- = 1.62 moles C₂H₆O
46.069 g

(Step 2)
Molarity = moles / volume (L)

Molarity = 1.62 moles C₂H₆O / 2.36 L

Molarity = 0.686 M