Determine the heat of reaction for the reaction: 4NH,(g) + 502(g) → 4NO(g) + 6H2O(g)
Using the following sets of reactions:
N2(g) + O2(g) → 2NO(g) AH = 180.6 kJ
N2(g) + 3H2(g) → 2NH3(g) AH = -91.8 kJ
2H.) +0,() → 2H 0(g) AH = -483.7 kJ

Construct the hypothetical phase diagram for metals a and b between room temperature (20c) and 700c, given the following information: * the melting temperature of metal a is 480c. • the maximum solubility of b in a is 4 wt% b, which occurs at 420c. • the solubility of b in a at room temperature is 0 wt% b. • one eutectic occurs at 420c and 18 wt% b–82 wt% a. • a second eutectic occurs at 475c and 42 wt% b–58 wt% a. • the intermetallic compound ab exists at a composition of 30 wt% b–70 wt% a, and melts congruently at 525c.• the melting temperature of metal b is 600c. • the maximum solubility of a in b is 13 wt% a, which occurs at 475c. • the solubility of a in b at room temperature is 3 wt% a.

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

What is the value of keq for the reaction expressed in scientific notation?