Why is the enthalpy of formation of oxygen zero?

Which of the following is true about mixtures and compounds? A. A mixture contains different substances that are not chemically combined with one another. OB. A compound forms when different substances chemically combine to form a new substance. C.

2C4H10 (g) + 13O2 (g) → 8CO2 (g) + 10 H2O (g) How many moles of O2 are required to react completely with 5.00 moles C4H10?

A solution contains one or more of the following ions: Ag+, Ca2+, and Fe2+. When sodium chloride is added to the solution, no precipitate forms. When sodium sulfate is added to the solution, a white precipitate forms.

Which sample of matter has a crystal structure? (1) Hg (ℓ) (2) H2O (ℓ) (3) NaCl (s) (4) CH4 (g

One mole of any gas takes up how much space at stp

When does a spring tide take place? At the beginning of spring Only during the spring season Only after spring is over At any time

The highest cloud are known as

What is the mass of 4.85 X 10^22 atoms of iron (Fe) ?

If element x has 95 protons how many electrons does it have

Which of the following when dissolved in deionized water would make a good conducting solution? a) methanolb) sugarc) baking soda