Answer: Proteins are known as biomolecules and biomolecules are made of the elements Carbon, Hydrogen, Nitrogen, and Oxygen and the monomers of proteins are known as amino acids.
Standard temperature is 273 K
Standard pressure is 1 atm
We use the ideal gas equation to find out density of nitrogen gas in g/L
Ideal gas equation:

Molar mass of 
Pressure = 1 atm
Temperature = 273 K

= 1.25 g/L
Therefore, density of nitrogen gas at STP is 1.25 g/L
The crust of the Earth is thickest beneath the continents.
Answer:
C6H10Cl2
Explanation:
Convert mass % to mass
100g of the compound contains from each elements: 46,3g Cl; 47,05g C and 6,63g H
Molar mass
Cl = 35.5 g/mol
C = 12 g/mol
H = 1 g/mol
Find the number of moles:
Chlorine: 46.4g /35.5g/mol = 1,3 moles
Carbon: 47,05g/12 g/mol = 3,92 moles
hydrogen: 6,63g/1g/mol = 6,63 moles
Molar fraction:
Cl = 1,30/ 1,30 = 1
C = 3,92/ 1,30 = 3,01
H = 6,63/ 1.30 = 5,01
C3H5Cl = 76,5 g/ mol x 2 = 153 g/ mol
So multiply the molecular formula by two = C6H10Cl2
Answer:
E) Two of the above statements are true.
Explanation:
The options are:
A) Before the solution is titrated with HCl it is pink and when the color changes from pink to colorless, the moles of H*(aq) equals the moles of OH"(aq) used in the hydrolysis of the neutralized aspirin. <em>TRUE. </em>Before the solution is titrated, there is an excess of NaOH (Basic solution, phenolphtalein is pink). Then, at equivalence point, after the addition of HCl, the pH is acidic and phenolphtalein is colorless.
B) Before the solution is titrated with HCl it is colorless and when the color changes from colorless to pink, the moles of H*(aq) equals the excess moles of OH(aq) added. <em>FALSE. </em>As was explained, before the titration, the solution is pink.
C) 25.0 mL of 0.100 M NaOH was added to the sample to hydrolyze the neutralized aspirin in the solution. The titration with HCl allows us to determine the moles of excess OH(aq) added. Once we determine the moles of excess OH(aq), we can determine moles of OH"(aq) used in the hydrolysis of the neutralized aspirin, which is equal to the moles of aspirin in the recrystallized aspirin. <em>TRUE. </em>Aspirin requires an excess of base (NaOH) for a complete dissolution (Hydrolysis). Then, we add H+ as HCl to know the excess moles of OH-. As we know the added moles of OH-, we can find the moles of OH that reacted = Moles of aspirin.
D) We can determine the moles of aspirin in the recrystallized aspirin by titrating with the 0.100 M NaOH to the neutralization point. The purpose of the hydrolysis of the neutralized aspirin and the back-titration with the 0.100 M HCl is to confirm the moles of aspirin in the recrystallized aspirin. <em>FALSE. </em>NaOH can be added directly unyil neutralization point because, initially, aspirin can't be dissolved completely
E) Two of the above statements are true. <em>TRUE</em>
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Right option is:
<h3>E) Two of the above statements are true.</h3>