Answer:
The definition of a physical change is: A physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. The size or shape of matter may be changed but no chemical reactions occur.
An example of physical change is: crumbling a piece of paper or freezing water into ice.
It turns blue litmus into red .
Answer:
0.59 mol O₂
Explanation:
The balanced chemical equation for the decomposition of potassium chlorate (KClO₃) to produce potassium chloride (KCl) and oxygen gas (O₂) is the following:
2 KClO₃ → 2 KCl + 3 O₂
According to the equation, 3 moles of O₂ are produced from 2 moles of KClO ⇒ conversion factor: 3 mol O₂/2 mol KClO₃
Now, we calculate the number of moles of KClO₃ there is in 48.1 g, by dividing the mass into the molecular weight (Mw) of O₂:
Mw(KClO₃) = 39.1 g/mol + 35.4 g/mol + (16 g/mol x 3) = 122.5 g/mol
moles KClO₃ = mass KClO₃/Mw(KClO₃) = 48.1 g/(122.5 g/mol) = 0.3926 mol KClO₃
Finally, we multiply the moles of KClO₃ by the conversion factor to calculate the moles of O₂ produced:
0.3926 mol KClO₃ x 3 mol O₂/2 mol KClO₃ = 0.59 mol O₂
The burning of fossil fuels like coal, natural gas etc... leads to the emmission of carbondioxide which is a green house gas and leads to the increase of heat in the atmosphere. This results in greenhouse effect.