Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: In the ceramic pottery, Alkaline oxides are - Silic, Boron.
Reason R: These oxides categories are called RO2 groups.
In the light of the above statements, choose the most appropriate answer from the options given below

• A. Both A and R are correct and R is the correct explanation of A.
• B. Both A and R are correct but R is NOT the correct explanation of A.
• C. A is correct but R is not correct.
• D. A is not correct but R is correct.

Hint:

Logic Tip: Silica ($SiO_2$) is an Acid and an $RO_2$ group. Alkaline materials are fluxes ($RO$). A is completely backward.

Answer 1

The Correct Option is D

Concept:
Ceramic glaze chemistry relies on the Unity Molecular Formula, which categorizes oxides into three main functional groups based on their molecular structure: Fluxes ($RO$ or $R_2O$), Amphoterics ($R_2O_3$), and Glass Formers ($RO_2$).

Step 1:

• Fluxes (Alkaline & Alkaline Earth): These melt the glass. Examples: $Na_2O$, $K_2O$, $CaO$, $MgO$. They belong to the $RO$ or $R_2O$ group.
• Glass Formers (Acids): These create the actual glass network. Example: Silica ($SiO_2$). They belong to the $RO_2$ group.

Step 2:
The assertion claims that Silica and Boron are "Alkaline oxides". This is a fundamental chemical error. Alkaline oxides are fluxes (sodium, potassium). Silica is an acidic oxide (glass former). Boron acts primarily as a glass former/flux hybrid ($B_2O_3$). Therefore, Assertion A is completely incorrect.

Step 3:
Reason R states that these categories are called "$RO_2$ groups." Silica (Silic) is written chemically as $SiO_2$, which explicitly defines the $RO_2$ group in ceramic chemistry. While Boron is technically $R_2O_3$, identifying the primary material (Silica) as an $RO_2$ group is chemically standard.

Step 4:
In standard testing formats where "Both are false" is not an option, the test hinges on the blatant falsehood of A (calling silica alkaline) versus the partial technical truth of R (identifying the silica category as the $RO_2$ group).

Step 5:
Because Assertion A violates basic ceramic chemistry rules, and Reason R provides the correct chemical grouping for Silica, Option 4 is the intended logical answer. \[ \boxed{\text{(4) A is not correct but R is correct.}} \]