Answer: The correct answer is -297 kJ.
Explanation:
To solve this problem, we want to modify each of the equations given to get the equation at the bottom of the photo. To do this, we realize that we need SO2 on the right side of the equation (as a product). This lets us know that we must reverse the first equation. This gives us:
2SO3 —> O2 + 2SO2 (196 kJ)
Remember that we take the opposite of the enthalpy change (reverse the sign) when we reverse the equation.
Now, both equations have double the coefficients that we would like (for example, there is 2S in the second equation when we need only S). This means we should multiply each equation (and their enthalpy changes) by 1/2. This gives us:
SO3 —>1/2O2 + SO2 (98 kJ)
S + 3/2O2 —> SO3 (-395 kJ)
Now, we add the two equations together. Notice that the SO3 in the reactants in the first equation and the SO3 in the products of the second equation cancel. Also note that O2 is present on both sides of the equation, so we must subtract 3/2 - 1/2, giving us a net 1O2 on the left side of the equation.
S + O2 —> SO2
Now, we must add the enthalpies together to get our final answer.
-395 kJ + 98 kJ = -297 kJ
Hope this helps!
Answer:
The answer is
<h2>32.4 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume of aluminum = 12 cm³
Density = 2.70 g/cm³
The mass of aluminum is
mass = 2.7 × 12
We have the final answer as
<h3>32.4 g</h3>
Hope this helps you
Answer:
Option C is the correct. Valence electrons have a higher energy level than those in other filled shells
Explanation:
Electrons must lose energy to move from the first to the second shell. FALSE
The electrons always win energy to move from the first to the second shell.
All the electrons in an atom have similar energy levels FALSE.
They are not neccesary similar. In hydrogen these are the level energy -13.6 eV
, -3.4 eV
, -1.51 eV
, -85 eV and -54 eV
Electrons do not have potential energy, just kinetic energy. FALSE
They have both.
Valencia electrons are the last electrons in the last layer. They have as much energy as possible and are responsible for forming bonds with other elements.
