<u>Answer:</u> The percentage yield of
is 90.26%.
<u>Explanation:</u>
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
......(1)
Given mass of
= 80 g
Molar mass of
= 100 g/mol
Plugging values in equation 1:

For the given chemical equation:

By the stoichiometry of the reaction:
If 1 mole of
produces 1 mole of 
So, 0.8 moles of
will produce =
of 
Molar mass of
= 44 g/mol
Plugging values in equation 1:

The percent yield of a reaction is calculated by using an equation:
......(2)
Given values:
Actual value of
= 35.2 g
Theoretical value of
= 39 g
Plugging values in equation 2:

Hence, the percentage yield of
is 90.26%.
First off, With a hypothesis
Answer: B.They are arranged in energy levels
Explanation: Electrons orbit around the nucleus of an atom, and are not spread around equally throughout an atom because there are a different amount of electrons that can fit in each energy level or electron shell (both are the same thing). For example the first energy level can hold up to 2 electrons, the second shell can hold up to 8 electrons, the third can hold up to 18, and so on represented by the equation 2(n^2)
Volume Ba(OH)2 = 23.4 mL in liters :
23.4 / 1000 => 0.0234 L
Molarity Ba(OH)2 = 0.65 M
Volume HNO3 = 42.5 mL in liters:
42.5 / 1000 => 0.0425 L
number of moles Ba(OH)2 :
n = M x V
n = 0.65 x 0.0234
n = 0.01521 moles of Ba(OH)2
Mole ratio :
<span>Ba(OH)2 + 2 HNO3 = Ba(NO3)2 + 2 H2O
</span>
1 mole Ba(OH)2 ---------------- 2 moles HNO3
0.01521 moles ----------------- moles HNO3
moles HNO3 = 0.01521 x 2 / 1
moles HNO3 = 0.03042 / 1
= 0.03042 moles HNO3
Therefore:
M ( HNO3 ) = n / volume ( HNO3 )
M ( HNO3 ) = 0.03042 / 0.0425
M ( HNO3 ) = 0.715 M
Answer:
3.75 moles
Explanation:
The chemical equation is 2CH₃OH + 3O₂ -> 2CO₂ + 4H₂O
2 moles of CH₃OH are burned by 3 moles of O₂
For 2.5 moles of CH₃OH are burned by x moles of O₂
Let's solve for x :
2*x=2.5*3 => 2*x=7.5 => x=3.75 moles of O₂ are needed to burn 2.5 moles of CH₃OH