Which of the following represents an endothermic reaction? CH4 (g) + 202 (g) → CO2 (g) + 2H2O (g) + 890 kJ 2C2H6 (g) + 702 (g) → 4CO2 (g) + 6H20(g) + 3120 kJ 25O2 (g) → 25 (s) + 202 (g) + 376KJ 2H20 (g) + 572 kJ → 2H2 (g) + O2 (g)

The reaction below is a  exothermic or endothermic reaction. 2SO3(g) + Heat ⇋ 2SO2(g) + O2(g)

Use the following information to answer Questions 6-9: A sample of NH4NO3 with a mass of 5.0 g is dissolved in 40.1 g of deoinized water in a calorimeter.  The initial temperature of the water is 21.2 oC.  The final temperature of the solution is 15.4 oC.  The calorimeter constant = 25.2 J/oC. Is the following statement true or false? This process is exothermic.  True  False

Which of the following reactions is exothermic? C2H4(g) + O2(g) → 2C(s) + 2H2O(g) AH = 469.2 kJ O N204(g) + 57.6 kJ → 2NO2(g) C2H4(g) + 302(g) → 2CO2(g) + 2H2O(g) > AH = 1322.9 kJ PCI3(g) + Cl2(g)→ PCI5(g) + 92.5 kJ

The sugar arabinose, C5 H10 O5, is burned completely in oxygen in a calorimeter. C5 H10 O5 (8) + 502(g) → 5CO2(g) + 5H2 O(1) Burning a 0.541 g sample caused the temperature to rise from 20.00°C to 20.54°C. The heat capacity of the calorimeter and its contents is 15.2 kJ/°C. Calculate AH for the combustion reaction per mole of arabinose. ΔΗ+ kJ/mol

CH, (g) 20, (g) → CO, (g) + 2 H,O (g) + Exothermic or endothermic

A 3.59°C increase in temperature occurs when a 0.232 g sample of benzoic acid (C7H6O2) is combusted in a bomb calorimeter. A 1.81 °C increase in temperature occurs when a 0.303 g sample of citric acid (C6H8O7) is combusted in the same bomb calorimeter. The heat of combustion of benzoic acid is -26.37 kJ/g. What is the molar heat of combustion of citric acid? Reminder: Any heats of combustion will be negative since these are exothermic reactions.

The flame in a torch used to cut metal is produced by burning acetylene (C2H2)(26.04 g/mol) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251 kJ of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 22.5  × 104 kJ of heat?                                            2 C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g) ΔH = –2502 kJ

Calculate the enthalpy change for the reaction C2H2(g) + 2H2(g) → C2H6(g)     ΔrH = ? from the following information: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)    ΔrH = –2320 kJ/mol2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g)    ΔrH = –3040 kJ/mol2H2(g) + O2(g) → 2H2O(g)                         ΔrH = –572 kJ/mol

Which chemical reaction below yields the heat of formation of liquid ammonia (NH3)? 3H(g) + N(g) →→→ NH3(e) H₂ (g) + N2₂ (g)→→ NH3(e) 3/2 H₂ (g) + 1/2 N₂ (g)→ NH3 (e) 3H₂(g) + N₂ (g)→ 2NH3(e) 3/2 H₂(g) + N(g)→ NH3(e)