NaHCO3 is the chemical formula for which common household substance?

Introduction / Context:
This question links basic inorganic chemistry with everyday household substances. Many compounds used in kitchens and cleaning products have familiar common names as well as chemical names and formulas. Recognising that NaHCO3 corresponds to baking soda is a standard general science fact that helps in both exams and real life applications such as cooking and neutralising acids.

Given Data / Assumptions:

• Chemical formula given: NaHCO3.
• We need to match it with a common name.
• Options include borax, vinegar, lime, baking soda and bleaching powder.
• We assume standard commercial forms of these substances.

Concept / Approach:
NaHCO3 is sodium hydrogen carbonate, also called sodium bicarbonate. Its common household name is baking soda, used as a leavening agent in baking and as a mild antacid. Borax is sodium tetraborate, vinegar is a dilute solution of acetic acid, lime usually refers to calcium oxide or calcium hydroxide, and bleaching powder is calcium oxychloride. None of these other names corresponds to NaHCO3.

Step-by-Step Solution:
Step 1: Interpret the formula NaHCO3. Na stands for sodium, H for hydrogen, C for carbon and O3 for three oxygen atoms. Step 2: The IUPAC name of NaHCO3 is sodium hydrogen carbonate or sodium bicarbonate. Step 3: In common language, sodium bicarbonate used in kitchens is called baking soda. Step 4: Examine option D, baking soda, which is the usual name for NaHCO3 found on packets in grocery stores. Step 5: Option A, borax, is sodium tetraborate, usually written as Na2B4O7·10H2O, and is used in cleaning and glass making. Step 6: Option B, vinegar, is a solution of acetic acid CH3COOH in water, not a solid carbonate. Step 7: Option C, lime, refers to calcium oxide or calcium hydroxide, not a sodium salt. Step 8: Option E, bleaching powder, is calcium oxychloride, often written as Ca(OCl)Cl, and is not NaHCO3. Step 9: Thus, NaHCO3 corresponds to baking soda.

Verification / Alternative check:
You can verify this by recalling common exam lists that pair chemical names with formulas and uses. Baking soda, NaHCO3, is used in baking to produce carbon dioxide gas when it reacts with acids, causing dough to rise. It is also used in antacid tablets to neutralise excess stomach acid. Borax, lime and bleaching powder are usually mentioned in separate contexts, such as cleaning agents, construction materials and disinfectants, with clearly different formulas. This reinforces that NaHCO3 is baking soda.

Why Other Options Are Wrong:
Borax has a completely different composition and is a borate salt, not a hydrogen carbonate. Vinegar is a liquid acid solution, not a solid salt, and its main component is acetic acid. Lime refers to calcium based compounds and has formulas like CaO or Ca(OH)2. Bleaching powder is a chlorine containing calcium compound and is chemically distinct from sodium hydrogen carbonate. Therefore, none of these can represent NaHCO3.

Common Pitfalls:
Students sometimes mix up baking soda (NaHCO3) with baking powder, which is a mixture that usually contains baking soda plus an acid salt and starch. Another confusion is between washing soda, Na2CO3·10H2O, and baking soda, NaHCO3. Washing soda is used in cleaning and water softening, whereas baking soda is mainly used in cooking and as a mild antacid. Remembering the H in NaHCO3 as indicating hydrogen carbonate can help keep these formulas distinct.

Final Answer:
NaHCO3 is the chemical formula for baking soda.