JEE PYQ: P Block Elements Question 77
Question 77 - 2019 (12 Jan Shift 1)
Given:
(i) $\text{C (graphite)} + \text{O}_2(g) \to \text{CO}_2(g)$; $\Delta_r H^0 = x$ kJ mol$^{-1}$
(ii) $\text{C (graphite)} + \frac{1}{2}\text{O}_2(g) \to \text{CO}(g)$; $\Delta_r H^0 = y$ kJ mol$^{-1}$
(iii) $\text{CO}(g) + \frac{1}{2}\text{O}_2(g) \to \text{CO}_2(g)$; $\Delta_r H^0 = z$ kJ mol$^{-1}$
Based on the above thermochemical equations, find out which one of the following algebraic relationships is correct?
(1) $x = y + z$
(2) $z = x + y$
(3) $y = 2z - x$
(4) $x = y - z$
Show Answer
Answer: (1)
Solution
Equation (i) can be obtained by adding equations (ii) and equation (iii). Therefore $\Delta H_1^0 = \Delta H_2^0 + \Delta H_3^0$, i.e. $x = y + z$.
BETA
