MCQ practice · SSC Chemistry Board questions · Chapter 6: Concept of Mole and Chemical Counting
How many atoms are there in one molecule of aluminium nitrate?
Think it through first, then pick an option.
- a 5
- b 9
- c 13
- d 15
Answer and explanation
Correct answer: c 13
Al(NO₃)₃: 1 Al + 3 N + 9 O = 13 atoms.
Why the other options are wrong
- a 5: 5 comes from taking AlNO₃; the right formula, Al(NO₃)₃, has 13.
- b 9: 9 counts only the atoms of the 3 NO₃ (3 × 3); the Al is left out.
- d 15: 15 counts 2 atoms too many; Al(NO₃)₃ has 1 + 3 + 9 = 13.
More board questions on this topic
- How many moles are there in 100 g of potassium dichromate?
- Which is the formula of aluminium carbonate?
- If enough vinegar is added to the reaction vessel, what is the…
- Of the stimulus:
Your account is open, so all 30,000+ MCQs from every chapter are yours. Start practising SSC Chemistry →
Want to keep going?
A free account carries you on to the next questions and opens 30,000+ MCQs from every chapter. Join before launch and Chirkut bundles are 60% off.
The ones you missed, worth one more look