Write the equilibrium expression for N2 (g) + 3 H2 (g) ↔ 2 NH3 (g) + heat I have no idea where to even start, due to the corona we have to learn by ourselves and my teacher is slacking off. Please Help!

 The equilibrium expression for a chemical reaction is written according to the law of mass action, which states that at a constant temperature, the rate of a chemical reaction is proportional to the product of the active masses of the reactants, each raised to a power equal to its coefficient in the balanced chemical equation.

For the reaction you've given, which is the synthesis of ammonia (NH₃) from nitrogen (N₂) and hydrogen (H₂), the balanced chemical equation is:

\[ N_2(g) + 3 H_2(g) \rightleftharpoons 2 NH_3(g) + heat \]

This is an exothermic reaction because heat is released.

The equilibrium expression, also known as the equilibrium constant expression, for the reaction is written as:

\[ K_{eq} = \frac{[NH_3]^2}{[N_2][H_2]^3} \]

Here, \( K_{eq} \) is the equilibrium constant, and the concentrations of the gases are represented within square brackets. The exponents correspond to the coefficients in the balanced equation. For the reactants and products that are gases, we use the partial pressures instead of concentrations, and the equilibrium constant is represented as \( K_p \). But in a more general approach, \( K_c \) is used with concentrations in moles per liter (M).

So for your reaction and in more common terms, if we are talking about concentrations:

\[ K_c = \frac{[NH_3]^2}{[N_2][H_2]^3} \]

Or for partial pressures:

\[ K_p = \frac{P_{NH_3}^2}{P_{N_2}P_{H_2}^3} \]

Note that in the expression for \( K_{eq} \), we do not include solids or liquids because their concentrations do not change during the reaction and are incorporated into the equilibrium constant value.