[figure] The total number of hydrogen atoms in product A and product B is .
Answer
10
Solution
In ethanol (alcoholic NaOH), OH- acts as a base ⇒ β-elimination (dehydrohalogenation):
CH3CH2Br NaOH/C2H5OH CH2=CH2 ⇒ A = ethene (4 H)
In water (aqueous NaOH), OH- acts as a nucleophile ⇒ substitution:
CH3CH2Br NaOH/H2O CH3CH2OH ⇒ B = ethanol (6 H)
∴ Total H = 4 + 6 = 10
Answer: 10