Option D
A precipitate is the term for a solid that forms when two solutions are mixed
<u>Explanation:</u>
A solid set from a couple of solutions is termed a precipitate. A precipitate is an unsolved solid that makes when a pair of solutions are fused and react chemically. Unsolvable means that the solid will not melt. When the effect transpires in a liquid solution, the solid developed is denominated the 'precipitate'.
The substance that generates the solid to make is termed the 'precipitant'. Seldom the development of a precipitate symbolizes the existence of a chemical reaction. Precipitation may additionally transpire immediately from a supersaturated solution.
Gasoline contains C and H atoms. During combustion, the carbon (C) from the fuel combines with oxygen (O2) from the air to produce carbon dioxide (CO2).
2 C8H18 + 25 O2 → 16 CO2 + 18 H2O.
Combustion reactions release large amounts of heat. They have negative enthalpy. A negative enthalpy represents an exothermic reaction, releasing heat. This reaction is spontaneous and exothermic, since we can obtain energy from the reaction; the ΔG (free energy) is negative (So 1 is true).
ΔG < 0, so the free energy of the system decreases with the reaction. Remember that when there is a negative ΔG the reaction goes from higher free energy to lower free energy, like in this case.
The kinetic energy causes the air molecules to move faster and they impact the container walls more frequently and with more force. The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles.
Answer: There are 
molecules present in 7.62 L of 
at 
and 722 torr.
Explanation:
Given : Volume = 7.62 L
Temperature = 
Pressure = 722 torr
1 torr = 0.00131579
Converting torr into atm as follows.
Therefore, using the ideal gas equation the number of moles are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
According to the mole concept, 1 mole of every substance contains 
atoms. Hence, number of atoms or molecules present in 0.244 mol are calculated as follows.
Thus, we can conclude that there are molecules present in 7.62 L of at and 722 torr.
