Solve Chemistry Problems: Methane, Oxygen, Carbon Dioxide, Water

[abalo3]

1. Methane and oxygen react to form carbon dioxide and water. What mass of water if formed if 3.2g of methane reacts with 12.8g of oxygen to produce 8.8g of carbon dioxide?

2. For the reaction:
I2 (g)------> I2(s) , DeltaH degree = -62.4 kJ at 25 degree C. Based on the information given, what is the DeltaH degree vap or DeltaH degree sub at 25 degree C??

3. What is the smallest angle of SF6?

4. For the reaction:
2CH4 (g) + Cl2 (g)------->2CHCl3 (l) + 3H2(g)
DeltaH degree= -118.6kJ . DeltaH degree f= -134.1 kJ/mol for CHCl3 (l). Find DeltaH degree f for CH4 (g).

5. When 200ml if 0.150M of hydrochloric acid is added to 125 mL of 0.175 M mg(OH)2, the resulting solution will be: (acidic, basic, neutral)?

6. What is the Celsuis temperature of 100.0 g of chlorine gas in a 40.0 L container at 800mmHg?

7. Calculate the energy change in kJ/mol for the reaction:
Li+(g) + F-(g) ------> Li(g) + F(g) using the following information :
Li (g) ----> Li+(g) + e- +520 kJ/mol
F(g) + e----->F-(g) -328 kJ/mol

 

[chemisttree]

I already turned in my homework (years ago)...

 

[Blueshift5]

1. To solve this problem, we can use the equation: CH4 + 2O2 -> CO2 + 2H2O. This means that for every 1 mole of methane, we need 2 moles of oxygen to produce 1 mole of water. Therefore, we can set up a proportion to find the mass of water produced: (3.2g CH4 / 16.04 g/mol) = (8.8g H2O / 18.02 g/mol). Solving for the unknown, we get 1.75g of water produced.

2. The reaction given is a phase change from gaseous iodine to solid iodine. This means that the DeltaH degree vap or DeltaH degree sub is the enthalpy change for the vaporization or sublimation of iodine. Since the reaction is spontaneous, the enthalpy change must be negative, so the DeltaH degree vap or DeltaH degree sub at 25 degree C is -62.4 kJ.

3. The smallest angle of SF6 can be found by dividing 360 degrees by the number of atoms in the molecule, which is 6. This gives us an angle of 60 degrees.

4. We can use the equation: DeltaH degree f (CH4) = DeltaH degree f (CHCl3) - 2(DeltaH degree f (H2)). Plugging in the given values, we get: DeltaH degree f (CH4) = -134.1 kJ/mol - 2(-285.8 kJ/mol) = -118.6 kJ/mol.

5. To determine the resulting solution, we can use the equation: moles of HCl = moles of Mg(OH)2. This means that there will be equal amounts of H+ and OH- ions in the solution, making it neutral.

6. To find the Celsius temperature, we can use the ideal gas law: PV = nRT. Rearranging for T, we get T = (PV)/(nR). Plugging in the given values, we get T = (800 mmHg)(40.0 L) / (0.100 mol)(62.36 L mmHg/mol K) = 516.1 K. Converting to Celsius, we get a temperature of 242.1 degrees Celsius.

7. To calculate the energy change, we can use