Answer:
0.109 g.
Explanation:
Equation of the reaction:
Na3PO4 + 3HCl --> 3NaCl + H3PO4
Number of moles of HCl = molar concentration × volume
= 0.1 × 0.04
= 0.004 mol.
By stoichiometry, 1 mole of Na3PO4 neutralises 3 moles of HCl. Therefore, number of moles of Na3PO4 = 0.004/3
= 0.0013 mol
Mass of Na3PO4 = molar mass × number of moles
= 0.0013 × 164
= 0.219 g
Since 50% of Na3PO4 was present in the sample. Let 100 g be the total mass of the substance
= 0.219 × 50 g/100 g
= 0.109 g.
<span>Kind of substance besides water:
The best example of hydrogen bonding excluding water is DNA. The two strands of polymers are connected by hydrogen bonds between the nucleotide bases</span>.
Answer:

Explanation:
Hello there!
In this case, for these problems about collecting a gas over water, we must keep in mind that once the gas has been collected, the total pressure of the system is given by the atmospheric pressure, in this case 1.01 atm. Next, since we also have water in the mixture, we can write the following equation:

Thus, by solving for the pressure of nitrogen and using consistent units, we obtain:

Answer: Option (a) is the correct answer.
Explanation:
A protein part of an enzyme is known as an apoenzyme. An apoenzyme combines with a cofactor, it is known as holoenzyme.
Without a cofactor an apoenzyme cannot function as cofactor helps in the formation of an active enzyme system and provides a specific site on enzyme for the substrate.
Whereas a non-protein chemical compound or metal ion that helps in the activity of enzyme as a catalyst is known as a cofactor. A metal ion cofactor can be bound directly to the enzyme or to a coenzyme.
The organic non-protein molecules which bind to the protein molecule to form an active enzyme is known as a coenzyme. Coenzymes are small size molecules which help the enzymes to act as a catalyst.
Therefore, we can conclude that the statement an apoenzyme can catalyze its reaction without its cofactor, is false.