A piece of gold jewelry weighs 11.54 g and has a volume of 0.675 cm3. The jewelry contains only gold (density = 19.3 g/cm3) and
1 answer:
Answer:
Percentage of gold = 84.6%
Explanation:
Suppose the jewelry has x g of gold and y g of silver
The mass of both is the total mass of the jewelry then:
x + y = 11.54
And as the problem says the total volume is the sum of both volumes.
volume = mass / density
Solving the system you get:
x = 9.764 g
y = 1.776 g
The percentage of gold in the jewelry is:
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<u>Answer:</u> The partial pressure of oxygen gas is 2.76 bar
<u>Explanation:</u>
To calculate the number of moles, we use the equation given by ideal gas which follows:
where,
P = pressure of the gas = 5.57 bar
V = Volume of the gas = 2.19 L
T = Temperature of the gas = 298 K
R = Gas constant =
n = Total number of moles = ?
Putting values in above equation, we get:
To calculate the mole fraction of carbon dioxide, we use the equation given by Raoult's law, which is:
........(1)
where,
= partial pressure of carbon dioxide = 0.318 bar
= total pressure = 5.57 bar
= mole fraction of carbon dioxide = ?
Putting values in above equation, we get:
- Mole fraction of a substance is given by:
We are given:
Moles of nitrogen gas = 0.221 moles
Mole fraction of nitrogen gas,
Calculating the partial pressure of oxygen gas by using equation 1, we get:
Mole fraction of oxygen gas = (1 - 0.0571 - 0.448) = 0.4949
Total pressure of the system = 5.57 bar
Putting values in equation 1, we get:
Hence, the partial pressure of oxygen gas is 2.76 bar