How many moles of aluminum oxide al2o3 are in a sample with a mass of 204.0
2 answers:
Answer:
2 moles
Explanation:
Let us first start by calculating the molecular mass of Al₂O₃.
The mass of a mole of any compound is called it's molar mass. 1 molar mass 6.02 X 10²³, or Avogadro's number, of compound entities.
Say, 1 mole of Al₂O₃ has 6.02 X 10²³ of Al₂O₃ molecules/atoms. It also has 2*6.02 X 10²³ number of Al atoms and 3*6.02 X 10²³ number of O atoms.
Molecular mass of Al : 26.981539 u
Molecular mass of O: 15.999 u
Therefore, molecular mass of Al₂O₃ is:
= u
= 101.960078 u
This can be approximated to 102 u.
1mole weighs 102 u
So, 2moles will weigh 2*102 = 204 u
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Answer : This reaction is an exothermic reaction.
Explanation :
Endothermic reaction : It is defined as the chemical reaction in which the energy is absorbed from the surrounding.
In the endothermic reaction, the energy of reactant are less than the energy of product.
Exothermic reaction : It is defined as the chemical reaction in which the energy is released into the surrounding.
In the exothermic reaction, the energy of reactant are more than the energy of product.
Enthalpy of reaction : It is the difference between the energy of product and the reactant. It is represented as .
The balanced chemical reaction will be:
From the reaction we conclude that the heat energy is released during the reaction that means this reaction is an exothermic reaction.
Hence, the reaction is an exothermic reaction.
Answer:
4.90 g
Explanation:
Given that:
volume of t-pentyl alcohol = 5 mL
the standard density of t-pentyl alcohol = 0.805 g/mL
Recall that:
density = mass(in wt) /volume
mass = density × volume
mass = 0.805 g/mL × 5 mL
mass = 4.03 g
Volume of HCl used = 12 mL
The reaction for this equation is shown in the image attached below.
From the reaction,
88.15 g of t-pentyl alcohol reacts with concentrated HCl to yield 106.59 g pf t-pentyl chloride.
4.03 g of t-pentyl alcohol forms,
of t-pentyl chloride.
Therefore,
Theoretical yield of t-pentyl chloride = 4.90 g
