Question

A student uses gravimetric determination to find the water of hydration of a hydrated sample of cobalt (II) sulfate. The student’s sample contained 0.0098459 moles of anhydrous cobalt(II) sulfate (CoSO4) and 0.068921 moles of water (H2O). What is the formula of the cobalt(II) sulfate hydrate? (1 point)

Answer 1

CoSO₄.7H₂O

Step-by-step explanation:

Some salts are in its hydrate form to stabilize them. The hydrated form of CoSO₄ is:

CoSO₄.XH₂O

To find the hydration of the COSO₄ you must find the ratio of H₂O and CoSO₄ that is:

0.068921 moles H₂O / 0.0098459 moles CoSO₄ = 7

That means you have 7 moles of water per mol of CoSO₄ and the formula is:

CoSO₄.7H₂O