H-U3-Zone 3 Check (Themo Equat, Enthalpy of Form & Hess's Law)

Front

What is the conversion factor from kilocalories (kcal) to joules (J)?

Back

1 kcal = 4184 J.

Front

How many joules are in 1.8 kcal?

Back

7531 J.

Front

How many joules are in 0.2 kcal?

Back

837 J.

Front

How many joules are in 0.52 kcal?

Back

2176 J.

Front

What is Hess's Law?

Back

Hess's Law states that the total enthalpy change during a chemical reaction is the same, regardless of the number of steps the reaction takes.

Front

What is the enthalpy change (ΔH) for the reaction: 3Fe2O3 (s) + CO (g) → CO2 (g) + 2Fe3O4 (s)?

Back

ΔH = -59 kJ.

Front

How many kilocalories are in 126712 J?

Back

30 kcal.

Front

What is the formula to convert joules to kilocalories?

Back

kcal = J / 4184.

Front

What does ΔH represent in a chemical reaction?

Back

ΔH represents the change in enthalpy, indicating the heat absorbed or released during a reaction.

Front

What is the significance of a negative ΔH value?

Back

A negative ΔH value indicates that the reaction is exothermic, meaning it releases heat.