JEE Main · 2019 · Shift-ImediumRDX-023

50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. What is the amount of NaOH in 50…

Redox Reactions · Class 11 · JEE Main Previous Year Question

Question

50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. What is the amount of NaOH in 50 mL of the given sodium hydroxide solution?

Options
  1. a

    2 g

  2. b

    4 g

    ✓
  3. c

    1 g

  4. d

    8 g

Correct Answerb

4 g

Detailed Solution

Step 1 — Reaction of oxalic acid with NaOH:

H2C2O4+2NaOH→Na2C2O4+2H2O\mathrm{H_2C_2O_4 + 2NaOH \rightarrow Na_2C_2O_4 + 2H_2O}

Step 2 — Moles of oxalic acid used:

nH2C2O4=0.5 M×50×10−3 L=0.025 moln_{\mathrm{H_2C_2O_4}} = 0.5\ \mathrm{M} \times 50 \times 10^{-3}\ \mathrm{L} = 0.025\ \mathrm{mol}

Step 3 — Moles of NaOH in 25 mL (stoichiometry 1:2):

nNaOH=2×0.025=0.05 moln_{\mathrm{NaOH}} = 2 \times 0.025 = 0.05\ \mathrm{mol}

Step 4 — Molarity of NaOH solution:

MNaOH=0.05 mol0.025 L=2 MM_{\mathrm{NaOH}} = \frac{0.05\ \mathrm{mol}}{0.025\ \mathrm{L}} = 2\ \mathrm{M}

Step 5 — Amount of NaOH in 50 mL of the same solution:

n=2 M×0.05 L=0.1 moln = 2\ \mathrm{M} \times 0.05\ \mathrm{L} = 0.1\ \mathrm{mol}

m=0.1×40 g mol−1=4 gm = 0.1 \times 40\ \mathrm{g\ mol^{-1}} = \mathbf{4\ \mathrm{g}}

Answer: Option (2) — 4 g

Practice this question with progress tracking

Want timed practice with adaptive difficulty? Solve this question (and hundreds more from Redox Reactions) inside The Crucible, our adaptive practice platform.

Practice in The Crucible →Browse Redox Reactions chapter →

More JEE Main Redox Reactions PYQs

2025hard

0.1 M solution of KI reacts with excess of H2SO4 and KIO3 solution. According to equation 5I- + IO3- + 6H+ - 3I2 + 3H2O Identify the correct statements: (A) 200 mL of KI solution reacts with 0.004…

2024medium

Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It should not undergo chemical change in air. (C) It should be…

2024easy

KMnO4 decomposes on heating at 513 K to form O2 along with

2024easy

Given below are two statements: Statement (I): Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide solution. Statement (II): In this titration phenolphthalein…

2023easy

Given below are two statements: Statement I: In redox titration, the indicators used are sensitive to change in pH of the solution. Statement II: In acid-base titration, the indicators used are…

View all 49 Redox Reactions PYQs →
50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. What is the… (JEE Main 2019) | Canvas Classes