Question

The pale yellow liquid bromine pentafluoride reacts violently with water to give a mixture of bromic acid and hydrofluoric acid .
(a) Write a balanced chemical equation for this reaction.

BrF5 + 3H2O HBrO3 + 5HF

(b) Determine the concentration (in moles per liter) of each of the acids that result from the complete reaction of 5.40×10-2 moles of bromine pentafluoride with enough water to give a solution volume of 783 mL.

bromic acid : ________M

hydrofluoric acid : ___________M

Answer 1

Answer:

The concentration of bromic acid (HBrO₃) is 0.069 moles/L

the concentration of hydrofluoric acid (HF) is 0.345 moles/L

Explanation:

(a) The balanced chemical equation for the reaction is

BrF₅ + 3H₂O → HBrO₃ + 5HF

The chemical equation is balanced

(b) To determine the concentration of each acids,

First, we will determine the different volume of the acids yielded

The solution volume is 783 mL = 0.783 L

From the balanced chemical equation,

1 mole of BrF₅ produces 1 mole of HBrO₃

Likewise, 1 mole of BrF₅ will produce 5 moles of HF

From the question,

5.40×10⁻² moles of bromine pentafluoride (BrF₅) reacted;

Hence, 5.40×10⁻² moles of HBrO₃ will be produced

and 5 × 5.40×10⁻² moles of HF will be produced.

Number of moles of HBrO₃ produced = 5.40×10⁻² moles

and Number of moles of HF produced = 2.7 × 10⁻¹ moles

From the formula,

Number of moles (n) = Concentration (C) × Volume (V)

Then,

Concentration (C) = Number of moles (n) / Volume (V)

For bromic acid (HBrO₃)

n = 5.40×10⁻² moles

Volume = 0.783L

Hence,

C = 5.40×10⁻² moles / 0.783L

C = 0.069 moles/L

This is the concentration of bromic acid (HBrO₃)

For hydrofluoric acid (HF)

n = 2.7 × 10⁻¹ moles

V = 0.783L

Hence,

C = 2.7 × 10⁻¹ moles / 0.783L

C = 0.345 moles/L

This is the concentration of hydrofluoric acid (HF)