A quantity of ice at $0^{\circ} \mathrm{C}$ is added to $64.3 \mathrm{~g}$ of water in a glass at $55^{\circ} \mathrm{C}$. After the ice melted, the temperature of the water in the glass was $15^{\circ} \mathrm{C}$. How much ice was added? The heat of fusion of water is $6.01 \mathrm{~kJ} / \mathrm{mol}$ and the specific heat is $4.18 \mathrm{~J} /\left(\mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)$.

A 35.8-g sample of cadmium metal was melted by an electric heater providing $4.66 \mathrm{~J} / \mathrm{s}$ of heat. If it took $6.92 \mathrm{~min}$ from the time the metal began to melt until it was completely melted, what is the heat of fusion per mole of cadmium?

How much heat is required to warm 1.50 L of water from 25.0$^{\circ}$C to 100.0$^{\circ}$C? (Assume a density of 1.0 g/mL for the water.)

Describe how you could liquefy the following gases: a. methyl chloride, $\mathrm{CH}_3 \mathrm{Cl}$ (critical point, $144^{\circ} \mathrm{C}$, 66 atm); b. oxygen, $\mathrm{O}_2$ (critical point, $-119^{\circ} \mathrm{C}, 50 \mathrm{~atm}$ ).

Explain why $15 \mathrm{~g}$ of steam at $100^{\circ} \mathrm{C}$ melts more ice than $15 \mathrm{~g}$ of liquid water at $100^{\circ} \mathrm{C}$.

Identify the phase transition occurring in each of the following.

a. Mothballs slowly become smaller and eventually disappear. b. Rubbing alcohol spilled on the palm of the hand feels cool as the volume of liquid decreases. c. A black deposit of tungsten metal collects on the inside of a lightbulb whose filament is tungsten metal. d. Raindrops hit a cold metal surface, which becomes covered with ice. e. Candle wax turns to liquid under the heat of the candle flame. 11.39 Use Figure $11.7$ to estimate the boiling point of diethyl ether, $\left(\mathrm{C}_2 \mathrm{H}_5\right)_2 \mathrm{O}$, under an external pressure of $350 \mathrm{mmHg}$.

Zinc metal reacts with hydrochloric acid according to the balanced equation :$\mathrm{Zn}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{ZnCl}_{2}(a q)+\mathrm{H}_{2}(g)$ When 0.103 g of Zn (s) is combin ed with enough HCI to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 $^{\circ} \mathrm{C}$ to 23.7 $^{\circ} \mathrm{C}$. Find $\Delta H_{\mathrm{rxn}}$ for this reaction as written. (Use 1.0 g/ mL for the density of the solution and 4.18 $\mathrm{J} / \mathrm{g} \cdot^{\circ} \mathrm{C}$ as the specific heat capacity.)

A 31.1 g wafer of pure gold initially at 69.3 °C is submerged into 64.2 g of water at 27.8 °C in an insulated container. What is the final temperature of both substances at thermal equilibrium?

A silver block, initially at 58.5$^{\circ} \mathrm{C}$, is submerged into 100.0 g of water at 24.8$^{\circ} \mathrm{C}$, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.2$^{\circ} \mathrm{C}$. What is the mass of the silver block?

Consider the thermoc hemical equ ation for the combustion of acetone ($C_3H_6O$), the main ingredient in nail polish remover: $C_3H_6O(l) + 4O_2(g) \longrightarrow 3CO_2(g) + 3 H_2O(g)$ $\Delta H_{\mathrm{rxn}}^{\circ}=-1790 \mathrm{kJ}$ If a bottle of nail polish remover contains 177 mL of acetone, how much heat is released by its complete combustion? The density of acetone is 0.788 g/ mL.

Nitrometh ane ($CH_3NO_2$) burns in air to produce significant amounts of heat. $2 \mathrm{CH}_{3} \mathrm{NO}_{2}(l)+^{3}_{2} \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{CO}_{2}(g)+3 \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{N}_{2}(g)$ $\mathbf{1} H_{\mathbf{rxn}}^{\mathbf{o}} = - 1418 kJ$ How much heat is produ ced by the comp lete reaction of 5.56 kg of nit rometh ane?

Suppose that 25 g of each substance is initiall y at 27.0 $^{\circ} \mathrm{C}$. What is th e final temperature of each substance upon absorbing 2.35 kJ of heat? a. gold b. silver c. aluminum d. water

Determine whether each process is exothermic or endothermic and indicate the sign of $\Delta H$ a. natural gas burning on a stove b. isopropyl alcohol evaporating from skin c. water condensing from steam

Consider two flasks that contain different pure liquids at $20^{\circ} \mathrm{C}$

The liquid in one flask, substance $\mathrm{A}$, has a molar mass of $100 \mathrm{~g} / \mathrm{mol}$ and has hydrogen bonding. The liquid in the other flask, substance B, has a molar mass of $105 \mathrm{~g} / \mathrm{mol}$ and has dipole-dipole interactions. a.. If the molecular structures of the compounds are very similar, which flask probably contains substance $\mathbf{A}$ ? b. If you were to increase the temperature of each of the flasks by $15^{\circ} \mathrm{C}$, how would the pictures change (assume that you stay below the boiling points of the liquids)?