Teacha
  • Courses
  • Mock Exams
  • For Tutors
  • For Schools
  • Pricing
Log InStart Free
  1. Past Questions
  2. /
  3. WAEC
  4. /
  5. Chemistry
  6. /
  7. 2002
  8. /
  9. Q37
Question 37

Consider the following equation: Cr2O2-7(aq) + 14H+(aq) + 6e- → 2Cr3+(ag) + 7H2O(1). The oxidation number of chromium changes from

  • A.-2 to + 3
  • B.-2 to + 6
  • C.+6 to +3
  • D.+7 to + 6
Objective

Question details

Exam body
WAEC
Subject
Chemistry
Year
2002
Question no.
#37
Type
Objective
Previous · Q36A visible change is observed when a strip of iron is placed in an aqueous… Next · Q38 Which of the following ions require the largest quantity of electricity for…

More from this paper

  • Q33Equal amounts of marble chips are reacted separately with 100cm 3 of…
  • Q34CuSO 4 5H 2 O can be obtained from an aqueous solution of copper (ll)…
  • Q35Which of the following compounds will leave a metal residue when heated?
  • Q39If two metallic ions of the same concentration migrate to a graphite cathode…
  • Q40When concentrated sodium chloride solution is electrolysed using inert…
  • Q41Which of the following processes takes place during the production of margarine…
See all Chemistry 2002 questions
Teacha

Africa's learning & exam readiness platform. Built for students, tutors, and schools.

Platform

  • Courses
  • Mock Exams
  • Past Questions

For You

  • I'm a Tutor
  • I'm a School
  • Pricing

© 2025 Teacha. Built for African learners, tutors, and schools. Teacha is not affiliated with WAEC, NECO, or JAMB. All past questions are sourced from publicly available materials.

Privacy PolicyTerms of UseCookie Policy