2. Baking soda is sodium bicarbonate (NaHCO3). When you heat baking soda, it breaks down into sodium carbonate powder (Na2CO3), water vapor, and carbon dioxide. The enthalpy of this reaction is 129 kJ. Write a correct thermochemical equation for this reaction, explain how you came up with this equation, and explain what it tells you about the reaction.

Question

lena772 · Answer

A Thermochemical Equation is a balanced stoichiometric chemical equation that includes the enthalpy change, ΔH

lena772 · Answer

Thermochemical equations are just like other balanced equations except they also specify the heat flow for the reaction.

anonymous · Answer

I wrote this out before. Is this the correct equation?

2NaHCO3 (s) --> Na2CO3 (s) + H2O (g) + CO2 (g) 
ΔH = 129 kj

lena772 · Answer

$$2NaHCO _{3}(s)\rightarrow Na _{2}CO _{3}(s)+H _{2}O(g)+CO _{2}(g)$$

lena772 · Answer

Yes, that equation is correct :)

lena772 · Answer

Above the arrow you will put "heat"

anonymous · Answer

Above the arrow?

lena772 · Answer

Yes sir.

anonymous · Answer

What is heat?

lena772 · Answer

You came up with this equation because the products of the reaction and reactant is given. You know the chemical formulas for water vapor and carbon dioxide because they are simple. You then balanced the equation.

lena772 · Answer

heat - energy perceived as temperature: a form of transferred energy that arises from the random motion of molecules and is felt as temperature, especially as warmth or hotness.

lena772 · Answer

It tells you you heat baking soda the reaction occurs. Heat is the catalyst in the reaction, therefor it is written above the arrow.

anonymous · Answer

Sorry I'm a little confused. These are great explanations so do I just write heat like this:
                  heat
2NaHCO3 (s) --> Na2CO3 (s) + H2O (g) + CO2 (g) 
And then do I leave this below it: ΔH = 129 kj

lena772 · Answer

A common characteristic of decomposition reactions is that they occur when a solid substance is heated

lena772 · Answer

Yes, you write heat just like that. You may wanna put 129 kj instead of heat since the enthalpy is given. 

Enthalpy is the amount of heat content used or released in a system at constant pressure

anonymous · Answer

Oh okay got it.

Could I ask you another question?

anonymous · Answer

@Lena772

lena772 · Answer

Yes. Close this post and make a new one for the next question.

anonymous · Answer

Okay :)