74.62 g of magnesium oxide is formed from 45.00 g magnesium so 74.62-45.00= 29.62 g of oxygen is consumed or in other words a new compound is formed in the burning of magnesium in oxygen with a heavier mass than the pure magnesium.
Answer:
A) SiO2 is the limiting reactant
B) Theoretical yield= 72333.3g
C) % yield =91.5%
Explanation:
SiO2(s) + 2C(s) --------------> Si(s) + 2CO(g)
n(SiO2)= 155000/60 = 2583.33 mols
n(C)= 79000/12= 3291.66 mols
a)SiO2 is the limiting reactant
According to the balanced reaction equation,
60g of SiO2 produced 28g of SiO2
155000g of SiO2 will produce 155000×28/60= 72333.3g
Therefore theoretical yield of Si= 72333.3g
% yield= 66200/72333.3×100/1 =91.5%
Chemical energy is the kind of energy stored in the bonds formed by atoms and molecules in chemical compounds and elements. This energy is released during a chemical reaction and heat is often given out in the process. These kind of reactions where heat is given out as a by product are called exothermic reactions.
The major factor that determines how much chemical energy a substance has is the mass of that substance. Mass is defined as the amount of matter in a substance.
The higher the mass of a substance, the more concentrated that substance is and subsequently the greater the number of atoms and molecules.
Logically, the higher the number of atoms and molecules then the greater the number of bonds in that substance and subsequently the more the amount of chemical energy stored therein.
A ground state electron configuration follows the Aufbau Principle that states that electrons should be filled up in orbitals in increasing energy. In the given sequences, the right configuration is
<span>1s2 2s2 2p6 3s2 3p6 4s2 3d8.
2) the possible confirmation that follows Aufbau's principle is
D. </span><span>-[Kr] 5s24d105p3</span>
