2Na + O2 -> NaO2
that name is :
sodium peroxide
This is equivalent to having a standard enthalpy change of reaction equal to 10.611 kJ
<u>Explanation</u>:
The standard enthalpy change of reaction, Δ
H
∘
, is given to you in kilojoules per mole, which means that it corresponds to the formation of one mole of carbon dioxide.
C
(s] + O
2(g]
→
CO
2(g]
Remember, a negative enthalpy change of reaction tells you that heat is being given off, i.e. the reaction is exothermic.
First to convert grams of carbon into moles,
use carbon's molar mass(12.011 g).
Moles of C = mass in gram / molar mass
= 0.327 g / 12.011 g
Moles of C = 0.027 moles
Now, in order to determine how much heat is released by burning of 0.027 moles of carbon to form carbon-dioxide.
= 0.027 moles C
393 kJ
Heat released = 10.611 kJ.
So, when 0.027 moles of carbon react with enough oxygen gas, the reaction will give off 10.611 kJ of heat.
This is equivalent to having a standard enthalpy change of reaction equal to 10.611 kJ
<u>Answer:</u>
<em>1) ∆H is positive
Endothermic
</em>
<em>2)
Endothermic </em>
<em>3) Energy is absorbed
Endothermic
</em>
<em>4)
Exothermic
</em>
<em>5) ∆H is negtive
Exothermic
</em>
<em></em>
<u>Explanation:</u>
∆H is called as enthalpy change
It is also called as Heat of reaction
Energy is required for the bond to break a bond.
Energy is released when a bond is formed.

that is

We see in this equation, bonds between hydrogen and chlorine molecules gets broken and on the right side bond is formed in HCl.
If energy of products greater than energy of reactants then the reaction enthalpy change is endothermic .
If energy of products lesser than energy of reactants then the reaction enthalpy change is exothermic .
For example



(positive hence endothermic)



(negative hence exothermic)
Because ecosystems don't change over one day, they change over a long period of time. Plus, something that happens may be because of more than just one change.
Here are a few examples :)
iodine (I2)
naphthalene
aresenic (As)
ferrocene
water (H2O)
carbon dioxide (CO2)
Hope this helps :)