iran-konkur 2014 Q216

iran-konkur · Other · konkur-riazi_1393 Not Maths
216- If $\Delta H^\circ$ of combustion of methanol is $-700\ \mathrm{kJ.mol^{-1}}$, how many grams of it must be burned so that the released heat can bring 125 grams of water from $10^\circ\mathrm{C}$ to boiling at 1 atm pressure?
$$\left(\mathrm{c_{(water)} = 4.2\ J.g^{-1}.{}^\circ C^{-1},\ O = 16,\ C = 12,\ H = 1 : g.mol^{-1}}\right)$$
(1) $2/16$ (2) $1/68$ (3) $2/52$ (4) $3/36$
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Chemistry 120-C Page 18
\textbf{216-} If $\Delta H^\circ$ of combustion of methanol is $-700\ \mathrm{kJ.mol^{-1}}$, how many grams of it must be burned so that the released heat can bring 125 grams of water from $10^\circ\mathrm{C}$ to boiling at 1 atm pressure?

$$\left(\mathrm{c_{(water)} = 4.2\ J.g^{-1}.{}^\circ C^{-1},\ O = 16,\ C = 12,\ H = 1 : g.mol^{-1}}\right)$$

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(1) $2/16$ \qquad (2) $1/68$ \qquad (3) $2/52$ \qquad (4) $3/36$
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