Answer:
A physicist
Explanation:
A physicist is one who deals with matter energy and how they are related
Answer:
a) False
b) False
c) True
Explanation:
a) Most sulfur oxides formed during combustion come from sulfur in the air: The sulfur burns in presence of oxygen to produce sulfur oxides, the source of sulfur is anthropogenic activities (Human activities).
So the given statement is false.
b) A flue gas scrubber removes SO2 pollution in a coal-fired power plant by using lime to convert the SO2 into alcohols:
False
The lime reacts with sulfur dioxide to give carbon dioxide and calcium sulfite.
c) True
c)
Answer:
D. The side chains of D-Arg and D-Lys are not positioned to bind correctly at the active site
Explanation:
Stereospecificity is the ability to distinguish between stereoisomers of of a particular compound. L- and D- structures of compounds in living organisms are usually present in only one form due to stereospecificity. For example, naturally occuring amino acids in proteins are usually present as L-isomers.
Since enzyme are proteins, their active sites are composed of L-amino acid and they show stereospecificity in the reactions they catalyze. In their binding sites, only substrates complementary in structure can bind in order for catalysis to proceed. Therefore, only amino acids in the L- configuration are complementary to the active site of enzymes.
In the case of serine proteases, The side chains of -Arg and D-Lys will not be positioned properly for binding at the binding site of serine proteases, therefore, no catalysis will occur. On the other hand, L-Arg and L-Lys can bind to the catalytic site of serine proteases since they are complementary fits to the active site of the enzymes.
Answer:
in theoretical yield are obtained 2.61 g of aspirin from 2.0 g of salicylic acid and 5 mL of acetic anhydride
Explanation:
Aspirin (C9H8O4)
∴ mm C9H8O4 = 180 g/mol
salicylic acid (C7H6O3)
∴ mm C7H6O3 = 138 g/mol
acetic anhydride (C4H6O3)
∴ mm C4H6O3 = 102 g/mol
acetic acid (C2H4O2)
∴ mm C2H4O2 = 60 g/mol
reaction:
- C7H6O3 + C4H6O3 → C9H8O4 + C2H4O2
∴ g C7H6O3 = 2.0 g
∴ g C4H6O3 = (5.0 mL)(1.08 g/mL) = 5.4 g
limit reagent (L.R):
∴ n C7H6O3 = (2 g)(mol/138 g) = 0.0145 mol C7H6O3 (L.R)
∴ n C4H6O3 = (5.4 g)(mol/102 g) = 0.053 mol C4H6O3 (E.R)
theoretical yield:
Amount of product predicted by balanced equation when all limit reagent reacts
⇒ n C9H8O4 = (0.0145 mol C7H6O3)(mol C9H8O4/mol C7H6O3) = 0.0145 mol C9H8O4
⇒ g C9H8O4 = (0.0145 mol)(180 g/mol) = 2.61 g C9H8O4
