91Ó°ÊÓ

What is the relationship between a calorie and a kilocalorie? Which unit is larger?

Is a bond-making process exothermic or endothermic?

How much energy in calories is required to heat \(150 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O}\) from \(0^{\circ} \mathrm{C}\) to \(100^{\circ} \mathrm{C} ?\)

When \(1 \mathrm{~g}\) of steam condenses, \(540 \mathrm{cal}\) of energy is released. How many grams of ice can be melted with \(540 \mathrm{cal} ?\)

What is the heat of vaporization of a substance if 10,776 cal are required to vaporize \(5.05 \mathrm{~g}\) ? Express your final answer in joules per gram.

Is each chemical reaction exothermic or endothermic? a. \(2 \mathrm{SnCl}_{2}(\mathrm{~s})+33 \mathrm{kcal} \rightarrow \mathrm{Sn}(\mathrm{s})+\mathrm{SnCl}_{4}(\mathrm{~s})\) b. \(\mathrm{CH}_{4}(\mathrm{~g})+2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(\ell)+213 \mathrm{kcal}\)

Express 1,265 cal in kilocalories and in joules.

If 1,650 cal of heat are required to vaporize a sample that has a heat of vaporization of \(137 \mathrm{cal} / \mathrm{g}\), what is the mass of the sample?

Is each chemical reaction exothermic or endothermic? a. \(\mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{C}_{2} \mathrm{H}_{6}(\mathrm{~g})+137 \mathrm{~kJ}\) b. \(\mathrm{C}(\mathrm{s}\), graphite \()+1.9 \mathrm{~kJ} \rightarrow \mathrm{C}(\mathrm{s}\), diamond \()\)

Express \(9,043.3 \mathrm{~J}\) in calories and in kilocalories.