<u>Answer:</u> The number of moles of gas present is 0.276 moles
<u>Explanation:</u>
To calculate the number of moles of gas, we use the equation given by ideal gas:
PV = nRT
where,
P = Pressure of the gas = 725 mm Hg
V = Volume of the gas = 7.55 L
n = number of moles of gas = ?
R = Gas constant = 
T = Temperature of the gas = 
Putting values in above equation, we get:

Hence, the number of moles of gas present is 0.276 moles
Answer:
The mass of copper = 208.26 grams.
Explanation:
Density = mass / volume
8.9 = mass / 23.4
mass = 8.9 * 23.4
= 208.26 grams.
Answer:
A. Solution, Colloid, Suspension
Hope i could help
Answer:
3. NaNO3
Explanation:
Below the line on TABLE G in the reference tables at 40C
3.125 i believe is the answer