From the equation;
4 Al + 3 O2 = 2 Al2O3
The mole ratio of Oxygen is to Aluminium hydroxide is 3:2.
Therefore; moles of Al2O3 is
(0.5/3 )× 2 = 0.333 moles
Therefore; The moles of aluminium oxide will be 0.333 moles
Explanation:
here is the answer to your question
Answer:
Hey there!
22.0 has three significant figures.
Let me know if this helps :)
1. CH4
2. Br2
3. 25 g/mol
Graham's law indicates that the rate of diffusion is inversely proportional to the square root of its molecular weight. So the lighter the gas, the more rapid the diffusion. With that in mind, let's look at your questions:
1. A flask contains four gases: CH4, O2, C2H5, and N2. When the stopper is removed, which gas will diffuse the fastest?The answer here will be the lightest of the 4 gasses. So let's look at the molar mass of each gas:
CH4 = 16.04 g/mol
O2 = 32.00 g/mol
C2H5 = 29.06
N2 = 28.01
And CH4 is the lightest and therefore the fastest.
2. Which gas effuses 2.39 times slower than nitrogen gas? O2 Cl2 Br2 <--- I2
Let's start with the square root of 28.01 which is 5.292447449.
Now multiply by 2.39 and square the result to get the molar mass of the
desired gas which is (5.29*2.39)^2 = 12.64^2 = 159.77Now let's look at the molar masses.
O2 = 32
Cl2 = 70.91
Br2 = 159.81
I2 = 253.81
And the match goes to Br2
3. What is the molecular mass of a gas that effuses three times faster than radon? 16 g/mol 25 g/mol <--- 50 g/mol 67 g/mol,The molar mass of radon is 222 g/mol. So let's get the square root, divide by
3, then square the result. So(sqrt(222)/3)^2 = (14.89966443/3)^2 = 4.966554809^2 = 24.66666667 g/mol.And of the available choices, 25 g/mol is the best match.
2.5 * 1/2.2 * 1000 = 1136 g
OR
2.5 * 454 = 1135 g
You can use either for your conversion.
