For 2SO₂(g) + O₂(g) → 2SO₃(g), the sign of ΔS°sys is:

The pH of 0.0050 M HNO₃ is:

Nails used to attach shingles to the roof are coated with an element to prevent corrosion. Choose the element from this list that most probably is used to coat roofing nails.

How much heat is required to warm 50.0 g of water (c = 4.184 J/g·°C) from 20.0 °C to 45.0 °C?

H₂ + I₂ ⇌ 2HI has K = 49. Starting with 0.200 M of each reactant (no HI), the equilibrium [HI] is:

For 2H₂ + O₂ → 2H₂O, ΔH = −572 kJ. How much heat is released when 4.0 mol of H₂ burns?

A reaction has K = 2.0×10⁵ at 298 K. ΔG° is: (R = 8.314 J/mol·K)

A candy bar contains 250 food Calories (Cal). How many kJ is this? (1 Cal = 1 kcal; 1 cal = 4.184 J)

Using ΔG°f values (CO₂ −394.4, H₂O(l) −237.1, CH₄ −50.5 kJ/mol; O₂ = 0), ΔG° for CH₄ + 2O₂ → CO₂ + 2H₂O(l) is:

Doubling [A] quadruples the initial rate; doubling [B] has no effect. The rate law is: