I think c I’m not positive about the question but I think c
In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom.
Answer:
Mole fraction H₂O → 0.72
Mole fraction C₂H₅OH → 0.28
Explanation:
By the mass of the two elements in the solution, we determine the moles of each:
25 g . 1 mol/ 18g = 1.39 moles of water (solute)
25 g . 1 mol / 46 g = 0.543 moles of ethanol (solvent)
Mole fraction solute = Moles of solute / Total moles
Mole fraction solvent = Moles of solvent / Total moles
Total moles = Moles of solute + Moles of solvent
1.39 moles of solute + 0.543 moles of solvent = 1.933 moles → Total moles
Mole fraction H₂O = 1.39 / 1.933 → 0.72
Mole fraction C₂H₅OH= 0.543 / 1.933 → 0.28
Remember that sum of mole fractions = 1
Molar mass Pb = 207.2 g/mol
1 mole Pb ------------- 207.2
? mole Pb ------------ 9.51 x 10³
moles = 9.51 x 10³ * 1 / 207.2
moles = 9.51 x 10³ / 207.2
= 45.89 moles
hope this helps!
Answer:
cools as it rises, then sinks back down
Explanation:
The movement of air is a convection current. Convection currents occur when warm air rises, cools down, and sinks due to gained density, replacing the warm air closer to the ground, creating a cycle.
