Answer:
Once ignited, a ribbon of magnesium metal burns freely in air to form solid magnesium oxide in the form of a white powder. The reaction is plainly spontaneous even though ΔS is negative.
The mass for of aluminum that is produced by the decomposition of 5.0 Kg Al2O3 is 2647 g or 2.647 Kg
calculation
Write the equation for decomposition of Al2O3
Al2O3 = 2Al + 3 O2
find the moles of Al2O3 = mass/molar mass
convert 5 Kg to g = 5 x1000 = 5000 grams
molar mass of Al2O3 = 27 x2 + 16 x3 = 102 g/mol
moles =5000 g/ 102 g/mol = 49.0196 moles
by use of mole ratio between Al2O3 to Al which is 1:2 the moles of Al = 49.0196 x2 =98.0392 moles
mass of Al = moles x molar mass
= 98.0392 moles x 27g/mol = 2647 grams or 2647/1000 = 2.647 Kg
Physical changes only affect the appearance of an object. While chemical happens to the chemical make up and cannot be reversed. Think of it this way- physical change is like hair tint , it wears off- chemical is like permanent hair dye, it's permanent.
Answer:Option D
Explanation: Its Just the right answer :)
I think it is d because it talks about other things the other ones finest talk about so go with d or c I hope you get it right good luck
