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.
Explanation:
The equation doesn't satisfy the Law of Conservation of Matter because There are more oxygen atoms after the reaction than there were before the reaction.
Therefore,
Option C is correct ✔
Answer:
These tests determine the solubility of the compounds formed upon adding the test solution
Explanation:
Addition of Ba(NO₃)₂ will cause a precipitate ((Ba)₂SO₄) to form in the solution of (NH₄)₂SO₄. No precipitates will form in the other unknown solutions. Thus, whether or not the solution is ammonium sulfate can be determined.
Addition of NaCl solution will cause a precipitate (AgCl) to form in the solution of AgNO₃. No precipitates will form in the other unknown solutions. Thus, whether or not the solution is silver nitrate can be determined.
If no precipitates form, then the unknown solution must be KCl.
Answer:
recording the wavelength of light
Explanation:
When an appropriate measure of energy say in the form of light of a certain wavelength, is supplied, electrons have a tendency to absorb the energy and get excited to a higher energy level. Conversely, if an electron is already at a higher energy state it will emit energy in the form of light (or heat) and return to a more stable lower energy state.
