Which has the incorrect name-formula combination?
A) Chromium(II) sulfate-CrSO
B) Cobalt (III) nitrate – Co(NO),
C) Nickel (II) nitrite – Ni(NOO₂) a
D) Manganese(III) sulfite – Mn(SSO)
The Correct Answer and Explanation is :
Let’s go through each option to identify the incorrect name-formula combination:
A) Chromium(II) sulfate – CrSO
Chromium(II) sulfate should contain chromium with a +2 charge (Cr²⁺) and sulfate (SO₄²⁻) ions. Therefore, the correct formula should be CrSO₄ (one chromium ion for each sulfate ion). The formula CrSO is incorrect because it lacks the proper number of oxygen atoms for the sulfate ion.
B) Cobalt(III) nitrate – Co(NO₃)₃
Cobalt(III) has a +3 charge (Co³⁺), and nitrate (NO₃⁻) has a -1 charge. To balance the charges, we need three nitrate ions for every cobalt ion. Therefore, the correct formula is Co(NO₃)₃, which matches the name provided.
C) Nickel(II) nitrite – Ni(NO₂)₂
Nickel(II) has a +2 charge (Ni²⁺), and nitrite (NO₂⁻) has a -1 charge. To balance the charges, we need two nitrite ions for every nickel ion. The correct formula is Ni(NO₂)₂, which matches the name provided.
D) Manganese(III) sulfite – Mn(SSO)
Manganese(III) has a +3 charge (Mn³⁺), and sulfite (SO₃²⁻) has a -2 charge. The formula should balance the charges, which means we need two sulfite ions for every manganese ion. The correct formula should be Mn₂(SO₃)₃. The formula Mn(SSO) is incorrect because “SSO” is not a proper chemical notation, and it does not correctly represent sulfite ions.
Correct Answer:
A) Chromium(II) sulfate – CrSO is the incorrect name-formula combination.
Explanation:
Chromium(II) sulfate involves chromium with a +2 oxidation state (Cr²⁺) and sulfate ions (SO₄²⁻). The formula CrSO is incorrect because it doesn’t account for the correct stoichiometry of chromium and sulfate ions. The correct formula should be CrSO₄, where one chromium ion pairs with one sulfate ion to balance the charges. This combination results in a neutral compound.