Lithium, Sodium, Potassium; any of the Alkali Metals, which are farthest left on the periodic table. This is because they only have one electron in their outermost shell, so they would rather lose an electron rather than try to gain 7 to achieve that full outer shell.
Answer:
See explanation below
Explanation:
The question is incomplete. However, here's the missing part of the question:
<em>"For the following reaction, Kp = 0.455 at 945 °C: </em>
<em>C(s) + 2H2(g) <--> CH4(g). </em>
<em>At equilibrium the partial pressure of H2 is 1.78 atm. What is the equilibrium partial pressure of CH4(g)?"</em>
With these question, and knowing the value of equilibrium of this reaction we can calculate the partial pressure of CH4.
The expression of Kp for this reaction is:
Kp = PpCH4 / (PpH2)²
We know the value of Kp and pressure of hydrogen, so, let's solve for CH4:
PpCH4 = Kp * PpH2²
*: You should note that we don't use Carbon here, because it's solid, and solids and liquids do not contribute in the expression of equilibrium, mainly because their concentration is constant and near to 1.
Now solving for PpCH4:
PpCH4 = 0.455 * (1.78)²
<u><em>PpCH4 = 1.44 atm</em></u>
Answer:
D. Separating a salt solution by evaporating the water
Explanation:
B. Allowing a nail to rust is a chemical change.
Becuase once the nail rust it turns into flakes and therefore is no longer a nail.
C. building a model rocket propelled by mixing baking soda and vinegar
By mixing baking soda (a powder) into vinegar ( a Acid) it causes a explosion...
the baking soda dissolve into the acid.... This a chemical reaction
A.creating salt by reacting sodium metal and chlorine gas
Sodium is salt but it says.... Sodium metal..... chlorine gas Changes color and it has a strong odor... chlorine gas with sodium metal turns it into salt.... it doesnt stay a metal or a gas it CHANGES.....
so therefore its a Chemical change
When A object or substance changes form or it causes a exsplosion or reaction it is a chemical change.
D. Separating a salt solution by evaporating the water
For a physical change your object may change color or shape but its still the same object.
salt in water ... The salt dont dissolve it just salty water.
So seperating salt by evaporating the water is a physical change.
Answer:
ΔH
°fCaO= -655.09 KJ/mol = ΔH
°fCaO
Explanation:
ΔH
°(reaction)a=ΔH
°f(product)-ΔH
°f(reactant)
where,
ΔH
°f(product)=is the standard heat of formation of products
-ΔH
°f(reactant)=is the standard heat of formation of reactants
The standard heat of formation of H
2
O
(
l
) is −
285.8
k
J
/
m
o
l
.
The standard heat of formation of Ca(OH
)2 is −
986.09
k
J
/
m
o
l
.
For the given reaction, the standard enthalpy change is calculated by the expression shown below.
ΔH
°(reaction)a=ΔH
°f(CaO+H2O)-ΔH
°f(Ca(OH)₂
65.2 = ΔH
°fCaO+( -265.8) -(-986.09)
= ΔH
°fCaO-265.8+986.09
65.2 = ΔH
°fCaO+ 720.29
65.2-720.29 = ΔH
°fCaO
-655.09 KJ/mol == ΔH
°fCaO
