What's the equation for the formation of NO2(g) from its elements in its standard states?
What's the equation for the formation of BF3(g) from its elements in its standard states?
What's the equation for the formation of C2H5OH(l) from its elements in its standard states?
What's the equation for the formation of CH3OH(l) from its elements in its standard states?
The equations for the formation of NO2(g), BF3(g), C2H5OH(l), and CH3OH(l) can be given as:
1. Formation of NO2(g):
2NO(g) + O2(g) -> 2NO2(g)
2. Formation of BF3(g):
B(s) + 3F2(g) -> BF3(g)
3. Formation of C2H5OH(l):
2C(s) + 3H2(g) + 1/2O2(g) -> C2H5OH(l)
4. Formation of CH3OH(l):
C(s) + 2H2(g) + 1/2O2(g) -> CH3OH(l)
To determine the equations for the formation of these compounds from their elements in their standard states, you need to understand the concept of standard enthalpy of formation (∆Hf°).
The standard enthalpy of formation (∆Hf°) is the enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states. The standard state of an element is its most stable form at a given temperature and pressure, usually taken to be 25 degrees Celsius and 1 atmosphere of pressure.
To find the equation for the formation of a compound, you can use the standard enthalpy of formation values for the elements involved. The equation should represent the formation of the compound from its constituent elements in their standard states, with coefficients adjusted to balance the equation.
1. Formation of NO2(g):
The standard enthalpy of formation of NO2(g) is +33.2 kJ/mol. The balanced chemical equation for its formation is:
1/2 N2(g) + O2(g) → NO2(g)
2. Formation of BF3(g):
The standard enthalpy of formation of BF3(g) is -1139.5 kJ/mol. The balanced chemical equation for its formation is:
B(s) + 3/2 F2(g) → BF3(g)
3. Formation of C2H5OH(l):
The standard enthalpy of formation of C2H5OH(l) is -277.6 kJ/mol. The balanced chemical equation for its formation is:
2 C(s) + 3 H2(g) + 1/2 O2(g) → C2H5OH(l)
4. Formation of CH3OH(l):
The standard enthalpy of formation of CH3OH(l) is -238.6 kJ/mol. The balanced chemical equation for its formation is:
C(s) + 2 H2(g) + 1/2 O2(g) → CH3OH(l)
Note: In these equations, (g) represents a gaseous state, (s) represents a solid state, and (l) represents a liquid state. The coefficients in front of the elements or compounds are adjusted to ensure that the equation is balanced. Also, the standard enthalpy of formation values may vary slightly depending on the source, but they are generally close to the values given here.
It appears you are posting part of a problem from a delta H calculation or something similar. Sometimes it is best to post the entire problem.
All of these equations are done the same way. From the elements, the first two are
N2(g) + 1/2O2(g) ==> NO2(g)
B(s) + 3/2F2(g) ==> BF3(g)
If you're going somewhere else with this question, fractions won't do for the balanced equation.