Answer:
Explanation:
Hello!
In this case, since the undergoing chemical reaction is:
It is widely known that when a gas given off from a reaction is collected over water, we can compute its pressure by minusing the total pressure 762 mmHg and the vapor pressure of water at the experiment's temperature (20 °C) in this case 17.5 mmHg as shown below:
Next, by using the ideal gas equation we compute the yielded moles of oxygen considering the collected 313 mL (0.313 L):
Now, via the 3/2:1 mole ratio between oxygen and lithium chlorate (molar mass = 90.39 g/mol), we compute the original mass of decomposed lithium chlorate as follows:
Now, the percentage is computed as shown below:
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Answer:
9.39 × 10²² molecules
Explanation:
We can find the moles of gases (n) using the ideal gas equation.
P . V = n . R . T
where,
P is the pressure (standard pressure = 1 atm)
V is the volume
R is the ideal gas constant
T is the absolute temperature (standard temperature = 273.15 K)
There are 6.02 × 10²³ molecules in 1 mol (Avogadro's number). Then,
I believe it is water..... I think.
The molal concentration of the solution is 0.67 mol/kg.
The formula for molal concentration (<em>b</em>) is
<em>b</em> = moles of solute/kilograms of solvent.
Moles of solute = 8.0 g × (1 mol/24 g) = 0.333 mol
b = 0.333 mol/0.50 kg = 0.67 mol/kg