Which can be both an empirical and molecular formula of a stable compound?
A CH₂O
B P₂O₅
C NH₂
D CH₃ - AQA - A-Level Chemistry - Question 5 - 2018 - Paper 3
Question 5
Which can be both an empirical and molecular formula of a stable compound?
A CH₂O
B P₂O₅
C NH₂
D CH₃
Worked Solution & Example Answer:Which can be both an empirical and molecular formula of a stable compound?
A CH₂O
B P₂O₅
C NH₂
D CH₃ - AQA - A-Level Chemistry - Question 5 - 2018 - Paper 3
Step 1
Identify the formulas
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
We need to determine which of the given formulas can serve as both empirical and molecular formulas for a stable compound. The options provided are:
A: CH₂O
B: P₂O₅
C: NH₂
D: CH₃
Step 2
Analyze Option A: CH₂O
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
CH₂O is both an empirical formula (simplest ratio of atoms) and its own molecular formula (actual number of atoms in the molecule). Therefore, this can represent a stable compound.
Step 3
Analyze Option B: P₂O₅
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
P₂O₅ is a molecular formula but its empirical formula is P₁O₂, indicating it does not qualify.
Step 4
Analyze Option C: NH₂
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
NH₂, while it is a basic form, does not represent a stable compound as typically seen (it is the amine functional group) without being attached to another element.
Step 5
Analyze Option D: CH₃
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
CH₃ is an empirical formula but can also be considered as the molecular formula for a radical, hence not typically stable.
Step 6
Conclusion
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The only option that can be both an empirical and molecular formula of a stable compound is A: CH₂O.
