Why is coal regarded as a mixture and a pure substance

Reaction 1: C3H8 (g) + 5O2 (g) →3CO2 (g) + 4H2O (g), ΔH1 = - 2043 kJ. Reaction 2: 3C3H8 (g) + 15O2 (g) →9CO2 (g) + 12H2O (g), ΔH2 = ? Determine the value of ΔH2.

Which of the following methods can be used to separate salt and iron

Which option correctly orders the elements by increasing reactivity? Hint: Review your periodic table. Na < K < Li K < Na < Li Li < Na < K Na < Li < K

A 1.248 g sample of limestone rock is pulverized and then treated with 30.00 ml of 1.035 m hcl solution. the excess acid then requires 11.56 ml of 1.010 m naoh for neutralization.

How many moles are in 88.1 of magnesium

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?