A 32.5-g iron rod, initially at 22.7 $^{\circ} \mathrm{C}$, is submerged into an unknown mass of water at 63.2$^{\circ} \mathrm{C}$, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 59.5$^{\circ} \mathrm{C}$. What is the mass of the water?

How much heat is required to warm 1.50 kg of sand from 25.0 $^{\circ} \mathrm{C}$ to 100.0 $^{\circ} \mathrm{C}$?

Titanium reacts with iodine to form titanium(lll) iodide, emitting heat. $2 \mathrm{Ti}(s)+3 \mathrm{l}_{2}(g) \longrightarrow 2 \mathrm{Til}_{3}(s) \quad \triangle H_{\mathrm{rxn}}^{\circ}=-839 \mathrm{kJ}$ Determine the masses of titanium and iodine that react if $1.55 \times 10^{3}$ kJ of heat is emitted by the reaction.

What mass of natural gas ($CH_4$) must burn to emit 267 kJ of heat? $\mathrm{CH}_{4}(g)+2 \mathrm{O}_{2}(g) \longrightarrow \mathrm{CO}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(g)$ $\Delta H_{\mathrm{rxn}}^{\circ}=-802.3 \mathrm{kJ}$

A $32.5 \mathrm{~g}$ iron rod initially at $22.7^{\circ} \mathrm{C}$ is submerged into an unknown mass of water at $63.2^{\circ} \mathrm{C}$ in an insulated container the final temperature of the mixture upon reaching thermal equilibrium is $59.5^{\circ} \mathrm{C}$ what is the mass of the water?

Mothballs are composed primarily of the hydrocarbon naphth alene $(C_{10}H_8)$. When $1.025 ~\mathrm{g}$ of naphthalene burns in a bomb calorimeter, the temperature rises from $24.25 ^{\circ} \mathrm{C}$ to $32.33^{\circ} \mathrm{C}$. Find $\Delta E_{\mathrm{rxn}}$ for the combustion of naphthalene. The heat capacity of the bomb calorimeter, determined in a separate experiment , is $5.11~ \mathrm{kJ}/ ^{\circ} \mathrm{C}$.

A 2.74-g sample of a substance suspected of being pure gold is warmed to 72.1$^{\circ} \mathrm{C}$ and submerged into 15.2 g of water initially at 24.7$^{\circ} \mathrm{C}$. The final temperature of the mixture is 26.3$^{\circ} \mathrm{C}$. What is the heat capacity of the unknown substance? Could the su bstance be pure gold?

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.)

How much heat is required to warm 1.50 kg of sand from 30.0 $^o$C to 100.0 $^o$C? The heat capacity of sand is 0.84 $\mathrm{\dfrac{J}{g\ K}}$.

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?

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 1.025 g of naphthalene is burned in a bomb calorimeter, the temperature rises from 24.25 $\degree$C to 32.33 $\degree$C. Find ΔErxn for the combustion of naphthalene. The heat capacity of the calorimeter, determined in a separate experiment, is 5.11kJ/$\degree$ C. Express the change in energy in kilojoules per mole to three significant figures.

A calorimeter contained 75.0 g of water at 16.95 °C. A 93.3-g sample of iron at 65.58 °C was placed in it, giving a final temperature of 19.68 °C for the system. Calculate the heat capacity of the calorimeter. Specific heats are 4.184 $\mathrm{J\cdot g^{-1}\cdot°C^{-1}}$ for $\mathrm{H_2O}$ and 0.444 $\mathrm{J\cdot g^{-1}\cdot°C^{-1}}$ for Fe.

Consider the function $f(x)=\frac{e^{x}}{x-1}$. Find the equation of the tangent at the point where x = 2.

How might deforestation lead to desertification?