Question

The yellow liquid iodine pentafluoride reacts vigorously with water to give a mixture of iodic acid and hydrofluoric acid.

a. Write a balanced chemical equation for this reaction.
b. Determine the concentration (in moles per liter) of each of the acids that result from the complete reaction of 3.91×10-2moles of iodine pentafluoride with enough water to give a solution volume of 888 mL.

Answer 1

a) F₅I + 3 H₂O ⇒ HIO₃ + 5 HF

b) HIO₃ 4.40×10⁻² M

HF 2.20x10⁻¹ M

Step-by-step explanation:

Once we have balanced the equation we use stoichiometry to calculate the amount of product formed. Looking at the equation, we can see that the reaction of 1 mole of H₅I with 3 moles of water yields 1 mole of HIO₃ and 5 moles of HF, respectively.

Therefore, we can calculate:

For HIO₃:

1 mole F₅I ------------------------ 1 mole HIO₃

3.91×10⁻² moles F₅I ----------- x= 3.91×10⁻² moles HIO₃

For HF:

1 mole F₅I --------------------------- 5 moles HF

3.91×10⁻² moles F₅I --------------- x= 1.95x10⁻¹ moles HF

However, these moles are contained in 888 mL, to calculate the concentration in molarity we need to calculate the moles present in 1 liter, or 1000 mL of volume (this comes from the definition of molarity).

Then, for HIO₃:

888 mL -------------------- 3.91×10⁻² moles HIO₃

1000 mL ------------------- x= 4.40×10⁻² moles HIO₃

For HF:

888 mL ------------------- 1.95x10⁻¹ moles HF

1000 mL ------------------ x= 2.20x10⁻¹ moles HF