Question

What volume of $0.200MNaOH$ is needed to react completely with $2.54g$ iodine according to the equation:
$3I_2+6NaOH\to 5NaI+NaI{O}_3+3H_{2}O$

• A. $100.0mL$
• B. $40.0mL$
• C. $4.00mL$
• D. $2.00mL$

Answer 1

The correct option is A $100.0mL$

No. of moles of iodine = wt. of iodine/ its molar mass.

⇒ no.of moles of iodine = 2.54 / 254 = 0.01 mol.

According to the given equation, NaOH reacts with I₂ in 2 : 1 ratio.

∴ No. of moles go NaOH = 0.01 x 2 = 0.02 mol

We know that, Molarity = no. of moles of solute / Vol. of solution (in L)

⇒ Vol. of solution = no. of moles (of NaOH) / Molarity

⇒ Vol. of solution = 0.02 / 0.2 = 0.1 L or 100 mL.

Hence, option A is correct.