Question 1

Given w = 0,an endothermic reaction has which of the following properties?

Accepted Answer

The answer of Given w = 0,an endothermic reaction has...

Question 2

Which of the following processes is endothermic?

Accepted Answer

The answer of Which of the following processes is endothermic?
...

Question 3

How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g $\mathrm { mol } ^ { - 1 }$ and may be useful. 4PCl₃(g)? P₄(s)+ 6Cl₂(g) D_rH°= +1207 kJ

Accepted Answer

First, calculate the moles of PCl₃: 765 g / 137.32 g/mol = 5.57 mol. The reaction decomposes 4 moles of PCl₃ with ΔH° = +1207 kJ. Therefore, for 5.57 moles, the energy required is (5.57 mol / 4 mol) × 1207 kJ = 1.68 × 10³ kJ.

Question 4

What volume of benzene (C₆H₆,d = 0.88 g mL^-1,molar mass = 78.11 g mol^-1)is required to produce 1.5 × 10³ kJ of heat according to the following reaction? 2C₆H₆(l)+ 15O₂(g)→ 12CO₂(g)+ 6H₂O(g) D_rH°= -6278 kJ

Accepted Answer

The answer of What volume of benzene (C₆H₆,d = 0.88...

Question 5

Using the following equation for the combustion of octane,calculate the amount of moles of carbon dioxide formed from 100.0 g of octane.The molar mass of octane is 114.33 g $\mathrm { mol } ^ { - 1 }$ .The molar mass of carbon dioxide is 44.0095 g $\mathrm { mol } ^ { - 1 }$ . 2C₈H₁₈ + 25O₂ ? 16CO₂ + 18H₂O D_rH°= -11018 kJ

Accepted Answer

The answer of Using the following equation for the combustion...

Question 6

According to the following reaction,how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP)? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g)+ 6Cl₂(g)? 2BCl₃(g)+ 6HCl(g) D_rH°= -1396 kJ

Accepted Answer

At STP, 1 mole of any gas occupies 22.4 L. Therefore, 2.50 L of B2H6 is 2.50/22.4 = 0.1116 moles, and 5.65 L of Cl2 is 5.65/22.4 = 0.2522 moles. The reaction requires 6 moles of Cl2 per mole of B2H6, so Cl2 is in excess. The limiting reagent is B2H6. The reaction of 0.1116 moles of B2H6 releases 0.1116 * 1396 kJ = 155.8 kJ, which rounds to 156 kJ.

Question 7

Which of the following processes is endothermic?

Accepted Answer

An endothermic process is one that requires the input of energy in order to occur. In this case, only choice C describes a process where energy is absorbed (in the form of a photon) by an atom.

Question 8

Using the following equation for the combustion of octane,calculate the amount of grams of carbon dioxide formed from 100.0 g of octane.The molar mass of octane is 114.33 g mol^-1.The molar mass of carbon dioxide is 44.0095 g mol^-1. 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O D_rH°= -11018 kJ

Accepted Answer

To solve this problem, we need to use stoichiometry. From the balanced equation, we can see that for every 2 moles of octane burned, 16 moles of carbon dioxide are produced.

First, we need to convert the given mass of octane to moles:

100.0 g octane x (1 mol octane/114.33 g octane) = 0.874 mol octane

Next, we can use the mole ratio from the balanced equation to find the number of moles of carbon dioxide produced:

0.874 mol octane x (16 mol CO2/2 mol octane) = 6.992 mol CO2

Finally, we can convert moles of CO2 to grams:

6.992 mol CO2 x 44.0095 g CO2/mol = 307.9 g CO2

Therefore, the answer is B.

Question 9

According to the following thermochemical equation,what mass of HF (in g)must react to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s)+ 4HF(g)→ SiF₄(g)+ 2H₂O(l) D_rH°= -184 kJ

Accepted Answer

The answer of According to the following thermochemical equation,what mass...

Question 10

Identify what a coffee cup calorimeter measures.

Accepted Answer

A coffee cup calorimeter measures the heat absorbed or released in a chemical reaction in an aqueous solution. This is represented by the change in enthalpy (ΔH), which is the amount of heat exchanged at constant pressure.

Question 11

How much energy is evolved during the reaction of 48.7 g of Al according to the reaction below? Assume that there is excess Fe₂O₃. Fe₂O₃(s)+ 2Al(s)→ Al₂O₃(s)+ 2Fe(s) D_rH°= -852 kJ

Accepted Answer

The answer of How much energy is evolved during the...

Question 12

Using the following equation for the combustion of octane,calculate the amount of moles of oxygen that reacts with 100.0 g of octane.The molar mass of octane is 114.33 g $\mathrm { mol } ^ { - 1 }$ .The molar mass of carbon dioxide is 44.0095 g $\mathrm { mol } ^ { - 1 }$ . 2C₈H₁₈ + 25O₂ ? 16CO₂ + 18H₂O D_rH°= -11018 kJ

Accepted Answer

First, calculate the moles of octane: 100.0 g / 114.33 g/mol = 0.874 moles. According to the balanced equation, 2 moles of octane react with 25 moles of oxygen. Therefore, 0.874 moles of octane will react with (0.874 moles * 25/2) = 10.93 moles of oxygen.

Question 13

According to the following reaction,how much energy is required to decompose 55.0 kg of Fe₃O₄? The molar mass of Fe₃O₄is 231.55 g $\mathrm { mol } ^ { - 1 }$ . Fe₃O₄(s)? 3Fe(s)+ 2O₂(g) D_rH°= +1118 kJ

Accepted Answer

To find the energy required, first convert 55.0 kg of Fe₃O₄ to moles using its molar mass (231.55 g/mol). Then, multiply the number of moles by the enthalpy change (ΔrH° = +1118 kJ/mol) to find the total energy required. This calculation results in approximately 2.66 × 10⁵ kJ.

Question 14

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g)+ 6Cl₂(g)? 2BCl₃(g)+ 6HCl(g) D_rH°= -1396 kJ

Accepted Answer

The answer of According to the following reaction,how much energy...

Question 15

Using the following equation for the combustion of octane,calculate the heat of reaction for 100.0 g of octane.The molar mass of octane is 114.33 g $\mathrm { mol } ^ { - 1 }$ . 2C₈H₁₈ + 25O₂ ? 16CO₂ + 18H₂O D_rH°= -11018 kJ

Accepted Answer

The heat of reaction for 100.0 g of octane is calculated by first determining the moles of octane (100.0 g / 114.33 g/mol = 0.874 mol), then using the given reaction enthalpy (-11018 kJ for 2 moles of octane) to find the heat for 0.874 moles: (0.874 mol / 2 mol) × -11018 kJ = -4820.37 kJ, which is approximately 4.82 × 10³ kJ.

Question 16

According to the following thermochemical equation,what mass of H₂O (in g)must form to produce 975 kJ of energy? SiO₂(s)+ 4HF(g)→ SiF₄(g)+ 2H₂O(l) D_rH°= -184 kJ

Accepted Answer

The answer of According to the following thermochemical equation,what mass...

Question 17

Using the following thermochemical equation,determine the amount of heat produced per kg of CO₂ formed during the combustion of benzene (C₆H₆). 2C₆H₆(l)+ 15O₂(g)→ 12CO₂(g)+ 6H₂O(g) D_rH°= -6278 kJ

Accepted Answer

The answer of Using the following thermochemical equation,determine the amount...

Question 18

Which of the following processes is exothermic?

Accepted Answer

The answer of Which of the following processes is exothermic?
...

Question 19

How much energy is evolved during the formation of 98.7 g of Fe according to the reaction below? Fe₂O₃(s)+ 2Al(s)→ Al₂O₃(s)+ 2Fe(s) D_rH°= -852 kJ

Accepted Answer

The molar mass of Fe is 55.85 g/mol, so 98.7 g of Fe is 1.77 mol. The reaction produces 2 mol of Fe per reaction, releasing 852 kJ. Therefore, 1.77 mol of Fe releases (1.77/2) * 852 kJ = 753 kJ.

Question 20

Using the following thermochemical equation,determine the amount of heat produced from the combustion of 24.3 g benzene (C₆H₆).The molar mass of benzene is 78.11 g $\mathrm { mol } ^ { - 1 }$ 2C₆H₆(l)+ 15O₂(g)? 12CO₂(g)+ 6H₂O(g) D_rH° = -6278 kJ

Accepted Answer

The combustion of 2 moles of benzene releases -6278 kJ. First, calculate the moles of benzene in 24.3 g: 24.3 g / 78.11 g/mol = 0.311 moles. Since 2 moles release 6278 kJ, 0.311 moles will release (6278 kJ / 2) * 0.311 = 977 kJ.

Quiz 6: Thermochemistry

Given w = 0,an endothermic reaction has which of the following properties?

Which of the following processes is endothermic?

How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g $\mathrm { mol } ^ { - 1 }$ and may be useful. 4PCl₃(g) ? P₄(s) + 6Cl₂(g) D_rH°= +1207 kJ

What volume of benzene (C₆H₆,d = 0.88 g mL^-1,molar mass = 78.11 g mol^-1) is required to produce 1.5 × 10³ kJ of heat according to the following reaction? 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) D_rH°= -6278 kJ

According to the following reaction,how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP) ? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Which of the following processes is endothermic?

Using the following equation for the combustion of octane,calculate the amount of grams of carbon dioxide formed from 100.0 g of octane.The molar mass of octane is 114.33 g mol^-1.The molar mass of carbon dioxide is 44.0095 g mol^-1. 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O D_rH°= -11018 kJ

According to the following thermochemical equation,what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) D_rH°= -184 kJ

Identify what a coffee cup calorimeter measures.

How much energy is evolved during the reaction of 48.7 g of Al according to the reaction below? Assume that there is excess Fe₂O₃. Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s) D_rH°= -852 kJ

According to the following reaction,how much energy is required to decompose 55.0 kg of Fe₃O₄? The molar mass of Fe₃O₄is 231.55 g $\mathrm { mol } ^ { - 1 }$ . Fe₃O₄(s) ? 3Fe(s) + 2O₂(g) D_rH°= +1118 kJ

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Using the following equation for the combustion of octane,calculate the heat of reaction for 100.0 g of octane.The molar mass of octane is 114.33 g $\mathrm { mol } ^ { - 1 }$ . 2C₈H₁₈ + 25O₂ ? 16CO₂ + 18H₂O D_rH°= -11018 kJ

According to the following thermochemical equation,what mass of H₂O (in g) must form to produce 975 kJ of energy? SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) D_rH°= -184 kJ

Using the following thermochemical equation,determine the amount of heat produced per kg of CO₂ formed during the combustion of benzene (C₆H₆) . 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) D_rH°= -6278 kJ

Which of the following processes is exothermic?

How much energy is evolved during the formation of 98.7 g of Fe according to the reaction below? Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s) D_rH°= -852 kJ

Using the following thermochemical equation,determine the amount of heat produced from the combustion of 24.3 g benzene (C₆H₆) .The molar mass of benzene is 78.11 g $\mathrm { mol } ^ { - 1 }$ 2C₆H₆(l) + 15O₂(g) ? 12CO₂(g) + 6H₂O(g) D_rH° = -6278 kJ

Quiz 6: Thermochemistry

Given w = 0,an endothermic reaction has which of the following properties?

Which of the following processes is endothermic?

How much energy is required to decompose 765 g of PCl3 according to the reaction below? The molar mass of PCl3 is 137.32 g mol−1\mathrm { mol } ^ { - 1 }mol−1 and may be useful. 4PCl3(g) ? P4(s) + 6Cl2(g) DrH° = +1207 kJ

What volume of benzene (C6H6,d = 0.88 g mL-1,molar mass = 78.11 g mol-1) is required to produce 1.5 × 103 kJ of heat according to the following reaction? 2C6H6(l) + 15O2(g) → 12CO2(g) + 6H2O(g) DrH° = -6278 kJ

According to the following reaction,how much energy is evolved during the reaction of 2.50 L B2H6 and 5.65 L Cl2 (both gases are initially at STP) ? The molar mass of B2H6 is 27.67 g mol−1\mathrm { mol } ^ { - 1 }mol−1 . B2H6(g) + 6Cl2(g) ? 2BCl3(g) + 6HCl(g) DrH° = -1396 kJ

Which of the following processes is endothermic?

Using the following equation for the combustion of octane,calculate the amount of grams of carbon dioxide formed from 100.0 g of octane.The molar mass of octane is 114.33 g mol-1.The molar mass of carbon dioxide is 44.0095 g mol-1. 2C8H18 + 25O2 → 16CO2 + 18H2O DrH° = -11018 kJ

According to the following thermochemical equation,what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO2. SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l) DrH° = -184 kJ

Identify what a coffee cup calorimeter measures.

How much energy is evolved during the reaction of 48.7 g of Al according to the reaction below? Assume that there is excess Fe2O3. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(s) DrH° = -852 kJ

According to the following reaction,how much energy is required to decompose 55.0 kg of Fe3O4? The molar mass of Fe3O4 is 231.55 g mol−1\mathrm { mol } ^ { - 1 }mol−1 . Fe3O4(s) ? 3Fe(s) + 2O2(g) DrH° = +1118 kJ

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B2H6 and 72.5 g Cl2? The molar mass of B2H6 is 27.67 g mol−1\mathrm { mol } ^ { - 1 }mol−1 . B2H6(g) + 6Cl2(g) ? 2BCl3(g) + 6HCl(g) DrH° = -1396 kJ

Using the following equation for the combustion of octane,calculate the heat of reaction for 100.0 g of octane.The molar mass of octane is 114.33 g mol−1\mathrm { mol } ^ { - 1 }mol−1 . 2C8H18 + 25O2 ? 16CO2 + 18H2O DrH° = -11018 kJ

According to the following thermochemical equation,what mass of H2O (in g) must form to produce 975 kJ of energy? SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l) DrH° = -184 kJ

Using the following thermochemical equation,determine the amount of heat produced per kg of CO2 formed during the combustion of benzene (C6H6) . 2C6H6(l) + 15O2(g) → 12CO2(g) + 6H2O(g) DrH° = -6278 kJ

Which of the following processes is exothermic?

How much energy is evolved during the formation of 98.7 g of Fe according to the reaction below? Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(s) DrH° = -852 kJ

Using the following thermochemical equation,determine the amount of heat produced from the combustion of 24.3 g benzene (C6H6) .The molar mass of benzene is 78.11 g mol−1\mathrm { mol } ^ { - 1 }mol−1 2C6H6(l) + 15O2(g) ? 12CO2(g) + 6H2O(g) DrH° = -6278 kJ

How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g $\mathrm { mol } ^ { - 1 }$ and may be useful. 4PCl₃(g) ? P₄(s) + 6Cl₂(g) D_rH°= +1207 kJ

What volume of benzene (C₆H₆,d = 0.88 g mL^-1,molar mass = 78.11 g mol^-1) is required to produce 1.5 × 10³ kJ of heat according to the following reaction? 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) D_rH°= -6278 kJ

According to the following reaction,how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP) ? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Using the following equation for the combustion of octane,calculate the amount of grams of carbon dioxide formed from 100.0 g of octane.The molar mass of octane is 114.33 g mol^-1.The molar mass of carbon dioxide is 44.0095 g mol^-1. 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O D_rH°= -11018 kJ

According to the following thermochemical equation,what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) D_rH°= -184 kJ

How much energy is evolved during the reaction of 48.7 g of Al according to the reaction below? Assume that there is excess Fe₂O₃. Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s) D_rH°= -852 kJ

According to the following reaction,how much energy is required to decompose 55.0 kg of Fe₃O₄? The molar mass of Fe₃O₄is 231.55 g $\mathrm { mol } ^ { - 1 }$ . Fe₃O₄(s) ? 3Fe(s) + 2O₂(g) D_rH°= +1118 kJ

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Using the following equation for the combustion of octane,calculate the heat of reaction for 100.0 g of octane.The molar mass of octane is 114.33 g $\mathrm { mol } ^ { - 1 }$ . 2C₈H₁₈ + 25O₂ ? 16CO₂ + 18H₂O D_rH°= -11018 kJ

According to the following thermochemical equation,what mass of H₂O (in g) must form to produce 975 kJ of energy? SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) D_rH°= -184 kJ

Using the following thermochemical equation,determine the amount of heat produced per kg of CO₂ formed during the combustion of benzene (C₆H₆) . 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) D_rH°= -6278 kJ

How much energy is evolved during the formation of 98.7 g of Fe according to the reaction below? Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s) D_rH°= -852 kJ

Using the following thermochemical equation,determine the amount of heat produced from the combustion of 24.3 g benzene (C₆H₆) .The molar mass of benzene is 78.11 g $\mathrm { mol } ^ { - 1 }$ 2C₆H₆(l) + 15O₂(g) ? 12CO₂(g) + 6H₂O(g) D_rH° = -6278 kJ