Rift Valley Examples
- East African
- Rhine Rift Valley (Germany)
- Baikal Rift Valley (Russia)
Rift Valley Facts/Characteristics
- Bordered by fault zones and separating land masses
- A portion of land that drops, forming a valley.
- Formed as tectonic plates move.
Fossils - Examples
- Bones
- Shells
- Exoskeletons
- Stone imprints of animals.
Non Examples of Fossils
- Stones
- rocks
- Some bones (If they are fossils they will be a lot heavier than other bones.
Hope this helps.
The answer is 492.8 g
1. Calculate a number of moles of a sample.
2. Calculate a molar mass of C3H8.
3. Calculate a mass of the sample.
1. Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance: 6.023 × 10²³ units per 1 mole
6.023 × 10²³ atoms : 1 mol =6.72 × 10²⁴ atoms : n
n = 6.72 × 10²⁴ atoms * 1 mol : 6.023 × 10²³ atoms = 1.12 × 10 mol = 11.2 mol
2. Molar mass (Mr) of C3H8 is sum of atomic masses (Ar) of its elements:
Ar(C) = 12 g/mol
Ar(H) = 1 g/mol
Mr(C3H8) = 3 * Ar(C) + 8 * Ar(H) = 3 * 12 + 8 * 1 = 36 + 8 = 44 g/mol
3. Mass (m) of a sample is number of moles (n) multiplied by molar mass (Mr) of C3H8:
m = n * Mr = 11.2 mol * 44 g/mol = 492.8 g
The empirical formula for 200 grams of an organic sample which contains carbon,hydrogen, and oxygen is C3H6O
