A chemical change affects on the molecular level of matter, which makes it irreversible. Combustion is a pretty good exmple. Physical changes are reversible and dont alter the formula. Hope this helped!
3rd one sorry if it’s wrong
Is this a multiple answer?
1 has a higher ionization dismal aoa
Answer:
Mass = 13.23 g
Explanation:
Given data:
Mass of oxygen = 48.0 g
Mass of propane burn = ?
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 48.0 g/ 32 g/mol
Number of moles = 1.5 mol
now we will compare the moles of propane and oxygen.
O₂ : C₃H₈
5 : 1
1.5 : 1/5×1.5 = 0.3 mol
Mass of propane burn:
Mass = number of moles × molar mass
Mass = 0.3 mol × 44.1 g/mol
Mass = 13.23 g