Question

which is not the correct chemical formula for the compound named?
○ nitric acid, hno₃
○ copper(ii) sulfate, cuso₄
○ potassium hydroxide, koh
○ phosphoric acid, h₃po₄
○ sodium carbonate, nahco₃

Explanation:

Step1: Recall chemical formula rules

Chemical formulas are based on element valences and compound - naming conventions.

Step2: Analyze nitric acid

Nitric acid has hydrogen ($H^+$) and nitrate ($NO_3^-$) ions, so its formula is $HNO_3$.

Step3: Analyze copper(II) sulfate

Copper(II) has a charge of $Cu^{2 + }$ and sulfate has a charge of $SO_4^{2 - }$, giving the formula $CuSO_4$.

Step4: Analyze potassium hydroxide

Potassium has a charge of $K^+$ and hydroxide has a charge of $OH^-$, resulting in the formula $KOH$.

Step5: Analyze phosphoric acid

Phosphoric acid has hydrogen ($H^+$) and phosphate ($PO_4^{3 - }$) ions, so the formula is $H_3PO_4$.

Step6: Analyze sodium carbonate

Sodium carbonate has sodium ($Na^+$) and carbonate ($CO_3^{2 - }$) ions. The correct formula is $Na_2CO_3$, while $NaHCO_3$ is sodium bicarbonate.

Answer:

sodium carbonate, $NaHCO_3$