219. Given the following reactions: $$\text{a)}\ \text{O}_2(g) + 2\text{ClF}(g) \rightarrow \text{Cl}_2\text{O}(g) + \text{OF}_2(g) \quad,\quad \Delta H = +168\ \text{kJ}$$ $$\text{b)}\ \text{O}_2(g) + 2\text{F}_2(g) \rightarrow 2\text{OF}_2(g) \quad,\quad \Delta H = -44\ \text{kJ}$$ $$\text{c)}\ 2\text{ClF}_3(l) + 2\text{O}_2(g) \rightarrow \text{Cl}_2\text{O}(g) + 3\text{OF}_2(g) \quad,\quad \Delta H = +394\ \text{kJ}$$ $\Delta H$ of the reaction producing $\text{ClF}_3(l)$ from gases $\text{ClF}$ and $\text{F}_2$ is how many kilojoules?
(1) $-135$ (2) $-270$ (3) $+518$ (4) $+259$
\textbf{219.} Given the following reactions:
$$\text{a)}\ \text{O}_2(g) + 2\text{ClF}(g) \rightarrow \text{Cl}_2\text{O}(g) + \text{OF}_2(g) \quad,\quad \Delta H = +168\ \text{kJ}$$
$$\text{b)}\ \text{O}_2(g) + 2\text{F}_2(g) \rightarrow 2\text{OF}_2(g) \quad,\quad \Delta H = -44\ \text{kJ}$$
$$\text{c)}\ 2\text{ClF}_3(l) + 2\text{O}_2(g) \rightarrow \text{Cl}_2\text{O}(g) + 3\text{OF}_2(g) \quad,\quad \Delta H = +394\ \text{kJ}$$
$\Delta H$ of the reaction producing $\text{ClF}_3(l)$ from gases $\text{ClF}$ and $\text{F}_2$ is how many kilojoules?
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(1) $-135$ \quad (2) $-270$ \quad (3) $+518$ \quad (4) $+259$
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