Assertion (A): Carbon cannot reduce MgO to magnesium at 1500 K. Reason (R): At 1500 K the Ellingham line of 2Mg + O2 -> 2MgO lies below that of 2C + O2 -> 2CO, so the coupled Delta G deg is positive. Choose:

Both A and R are true and R is the correct explanation of A

Both A and R are true but R is not the correct explanation of A

JEE Advanced levelSingle correct optionDifficulty 3 of 3mt102

Assertion (A): Carbon cannot reduce $MgO$ to magnesium at 1500 K. Reason (R): At 1500 K the Ellingham line of $2 Mg + O X_{2} 2 MgO$ lies below that of $2 C + O X_{2} 2 CO$ , so the coupled $Δ G^{\circ}$ is positive. Choose:

For carbon to reduce

MgO

the

CO

line must lie below the

MgO

line. At 1500 K the

MgO

line is lower (more negative), so

MgO + C Mg + CO

has a positive

Δ G^{\circ}

and A is true. R states exactly this, so it explains A.