Answer:
The percentage by mass of benzene in the solution is approximately 0.2%
Explanation:
The given parameters are;
The mass of the benzene solute dissolved in the gasoline solvent, m₁ = 1.56 g
The total volume of the benzene gasoline solution made, V = 998.44 mL
The density of gasoline, ρ = 0.7489 g/mL
Mass, m = Density, ρ × Volume, V
∴ The mass of gasoline in the 998.44 mL, solution = 0.7489 g/mL × 998.44 mL = 747.731716 g
The total mass of the solution = The mass of the benzene in the solution + The mass of the gasoline in the solution
∴ The total mass of the solution = 747.731716 g + 1.5 g = 749.231716 g

The percentage by mass of benzene in the solution = (1.5 g/749.231716 g)×100 ≈ 0.2% by mass.
If the element is a metal with one electron in its outermost energy level.
Answer:
A) 12 mol H2O.
Explanation:
Hello,
In this case, for the given reaction:

We notice that oxygen is in a 7:6 molar relationship with water, for that reason, the resulting moles of water turn out:

Thus, the answer is A) 12 mol H2O.
Best regards.
The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together
Answer:
The correct option is: protons; electrons
Explanation:
The electron transport chain contains a series of biomolecules that are involved in the transfer of electrons by redox reactions.
This process involves the transfer of electrons from an <u>electron donor molecule to an electron acceptor molecule</u>, resulting in the <u>release of energy.</u> Some amount of this energy is then used in <u>pumping the protons across the biological membrane.</u>