Thermal energy is absorbed as chemical reactions occur during the process of baking muffins. The batter for muffins often contains baking soda, NaHCO₃(s), which decomposes as the muffins are baked in an oven at 200.°C. The balanced equation below represents this reaction, which releases CO₂(g) and causes the muffins to rise as they bake. The H₂O(ℓ) is released into the air of the oven as it becomes a vapor.

2NaHCO₃(s)  +  heat → Na₂CO₃(s) + H₂O(ℓ) + CO₂(g)

67 Based on Table E, identify the polyatomic ion in the solid product of the reaction. [1]

HIGHLIGHT TO SEE THE ANSWER

68 State the direction of heat flow between the air in the oven and the muffin batter when the muffin batter is first placed in the preheated oven at 200.°C. [1]

HIGHLIGHT TO SEE THE ANSWER

 69 Compare the potential energy of the liquid water molecules to the potential energy of the water vapor molecules. [1]

 HIGHLIGHT TO SEE THE ANSWER