Vinegar - Acetic acid
Sour milk (Curd) - Lactic acid
Orange - Citric acid
Lemon - Citric acid
Tamarind - Tartaric acid
Ant sting - Methanoic acid
Tomato - Oxalic acid
Nettle sting - Methanoic acid
DONT TOUCH PEN, ONLY MIND CALCULATIONS WITHIN 40 SECS. REGULAR SPEED TEST. QUALITY STUDY MATERIALS. DEDICATED FACULTIES. ASSURANCE FOR SUCCESS.