Dimethyl ether, a useful organic solvent, is prepared in two steps. In the first step, carbon dioxide and hydrogen react to form methanol and water: CO₂(g) + 3 H₂(g) CH₂OH(1) + H₂O(1) ΔΗ=-131. kJ In the second step, methanol reacts to form dimethyl ether and water: 2 CH₂OH(1)→ CH₂OCH3(g) + H₂O(1) ΔΗ= 8. kJ Calculate the net change in enthalpy for the formation of one mole of dimethyl ether from carbon dioxide and hydrogen from these reactions. Round your answer to the nearest kJ.

When sulfuric acid dissolves in water, a great deal of heat is given off. The enthalpy change for this process is called the enthalpy of solution. To measure it, 175.0 g of water was placed in a coffee-cup calorimeter and chilled to 10.0 °C. Then 49.0 g of pure sulfuric acid, also at 10.0 °C, was added, and the mixture was quickly stirred with a thermometer. The temperature rose rapidly to 14.9 °C. Assume that the specific heat capacity of the resulting sulfuric acid solution is 4.19 J/g °C. Calculate the quantity of thermal energy transferred, Q, for the formation of this solution, and calculate the molar enthalpy of solution in kilojoules per mole of H₂SO4.

When 1.836 grams of sucrose (Molar mass 342.3 g/mol) is burned in a bomb calorimeter, the temperature of the calorimeter increases from 22.41°C to 26.63°C. If the heat capacity of the calorimeter is 4.900 kJ/°C, what is the heat of combustion of sucrose?

q represents the change in heat of a reaction or substance. The units of q are Joules (J) or kilojoules (kJ). For a well understood substance, we can calculate the specific heat which relates the mass of the substance in grams to the amount of heat in J required to raise that amount a certain temperature.  We call that specific heat.  The specific heat (Cs) of water is stated in the following way:  C s ( H 2 O ) = 4.186 J g ∘ C This means that it takes 4.186 J of energy to raise the temperature of 1g of water by 1ºC.  The relationship between q and Cs for a given substance is  where m is mass (g) and ∆T is the change in temperature in ºC (final temp - initial temp).  Calculate the heat change (q) in J when 4.297 grams of water is cooled from 3.967 ºC to -2.902 ºC. Enter your answer with one decimal place (tenths).  Pay careful attention to the sign of your answer.  The sign of ∆T is always the same as the sign for q.

When 6.54 grams of Zn is placed in 500.0 mL of 1.00 M CuSO4(aq) in a coffee cup calorimeter, it reacts completely to displace copper. The temperature of the solution rises from 20.0˚C to 30.4˚C. Assume the coffee cup itself gains no heat and that the solution has the same density (1.00 g/mL) and specific heat (4.184 J/g˚C) as pure water. (a) How much heat does the solution gain during this reaction? (in J)

At constant volume, the heat of combustion of a particular compound, compound A, is −3046.0 kJ/mol.−3046.0 kJ/mol. When 1.753 g1.753 g of compound A (molar mass =112.07 g/mol)=112.07 g/mol) is burned in a bomb calorimeter, the temperature of the calorimeter (including its contents) rose by 6.475 ∘C.6.475 ∘C. What is the heat capacity (calorimeter constant) of the calorimeter?     Suppose a 3.771 g3.771 g sample of a second compound, compound B, is combusted in the same calorimeter, and the temperature rises from 25.65 ∘C25.65 ∘C to 29.76 ∘C.29.76 ∘C. What is the heat of combustion per gram of compound B?

metal X =51.0g; specific heat capacity =0.44 J/C If metal X is heated to 86C and put into a calorimeter containing water (she=4.18 J/g°C ) at 23C. The final temperature of the water becomes 31C.   What is the mass of water?

Calculate enthalpy of reaction given reaction enthalpies for proposed steps in a process. K+(g) + Cl-(g) → KCI(s) KCI (LE) = ? Cl2(g) → 2CI(g) Cl-CI (BE) = 243 kJ/mol K(g) → K+(g) + 1e- K (IE) = 419 kJ/mol K(s) → K(g) K (AHsub) = 89.0 kJ/mol Cl(g) + 1e- → CI-(g) CI (EA) = -349 kJ/mol K(s) + 1/2C12(g) > KCI(s) KCI (AH;) = -436.5 kJ/mol

At constant volume, the heat of combustion of a particular compound is −3733.0 kJ/mol.−3733.0 kJ/mol. When 1.361 g1.361 g of this compound (molar mass=185.51 g/mol)(molar mass=185.51 g/mol) was burned in a bomb calorimeter, the temperature of the calorimeter, including its contents, rose by 8.567 ∘C.8.567 ∘C. What is the heat capacity (calorimeter constant) of the calorimeter?

33 of 35 > Macmillan Learning When methanol, CH3OH, is burned in the presence of oxygen gas, O₂, a large amount of heat energy is released. For this reason, it is often used as a fuel in high performance racing cars. The combustion of methanol has the balanced, thermochemical equation CH₂OH(g) + O₂(g) → CO₂(g) + 2 H₂O(1) ΔΗ = −764 kJ How much methanol, in grams, must be burned to produce 601 kJ of heat? mass: