The balanced equation for the above reaction is as follows;
2Al + 3Br₂ --> 2AlBr₃
stoichiometry of Al to Br₂ is 2:3
there are 5.0 mol of Al and 6.0 mol of Br₂
if Al is the limiting reactant,
if 2 mol of Al reacts with 3 mol of Br₂
then 5.0 mol of Al reacts with - 3/2 x 5 = 7.5 mol of Br₂
but only 6 mol of Br₂ is present therefore Br₂ is the limiting reactant.
if 3 mol of Br₂ reacts with 2 mol of Al
then 6.0 mol of Br₂ reacts with - 2/3 x 6 = 4 mol of Al
the molar ratio of Al to AlBr₃ is 2:2
the number of moles of AlBr₃ formed is 4 mol of AlBr₃
amount of excess Al - 5.0 mol - 4.0 mol = 1 mol
therefore at the end of the reaction,
1 mol of Al and 4 mol of AlBr₃ in the reaction vessel
Answer:
10.5g of KBr
Explanation:
molarity = moles of solute / litres of solution
we are given the volume of the solution in milliliters but the formula uses litres so we have to convert
to convert to liters we divide the number of milliliters by 1000 ( because 1 liter has 1000 milliliters. )
so liters of solution = 92.7/1000 = 0.0927 L
we can now plug in what we are given and solve for moles of solute
recall molarity = moles of solute / litres of solution
molarity = 0.955M and liters of solution = 0.0927L
so
multiply both sides by 0.0927
we're left with moles of solute = 0.0885285 moles
Finally we must convert moles to grams
Molar mass of KBr = 39.0983 + 79.904 = g/mol
Using dimensional analysis we get
the mol KBr cancel out on both sides and we get which is equal to 10.5g (rounded)
So we can conclude that 10.5g of KBr is dissolved in 92.7mL of a 0.955M solution.
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Answer:</h3>
250.756 moles He
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Explanation:</h3>
From the question we are given;
Volume, L = 685 L
Temperature, T = 621 K
Pressure, P = 189 × 10 kPa
We are required to calculate the number of moles of the gas,
Using the Ideal gas equation,
PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.
We can replace the known variables and constant in the equation to get the unknown variable, n.
Using ideal gas constant as 8.3145 L.kPa/K/mol
n = 250.756 moles
The moles of helium contained in the sphere is 250.756 moles
Answer:
C. Both observation 1 and observation 2.
Explanation:
The heliocentric model states that the Earth and planets revolve around the Sun at the center of the Solar System.
Observation 1 was answered by Nicolas Copernicus, father of the heliocentrism, in 1543. The reverse effect is an illusion created because the Earth revolves faster around the Sun than Mars.
And observation 2 also is explained by the model because the rotation of the earth made that the Stars be closer to it at different times of the year.
I hope this answer helps you.
1: An atom is nuclear energy that is extremely small. It is the smallest unit of matter that forms a chemical element. It is the building block for all matter in the universe. They are made up of even smaller particles. Particles that make up an atom are electrons, neutrons, and protons.
2. What’s different inside of an atom to make them into different elements is that the number of protons in an atom is the defining feature of an atom. This is what makes a element different from another.
Hope this helps!!