Answer: 
Explanation:
The balanced chemical equation :
To calculate the moles, we use the equation:
According to stoichiometry:
4 moles of 
produces = 902.0 kJ of energy
415.1 moles of produces =
of energy
Thus the change in enthalpy is
Answer: D.Aluminium Oxide 0.10, Magnesium Oxide 0.50
Explanation:
Number of moles of NaOH= number of moles × volume
Number of moles= 100/1000 × 2 = 0.2 moles
Since;
2 moles of NaOH yield 1 mole of Al2O3
0.2 moles of NaOH will yield 0.2 × 1/2 = 0.1 moles of Al2O3.
Number of moles of HCl= 800/1000 × 2 = 1.6 moles
If 1 mole of Al2O3 requires 6 moles of HCl
0.1 moles of Al2O3 requires 0.1 × 6 = 0.6 moles of HCl.
Number of moles of HCl left after reaction with Al2O3 = 1.6- 0.6 = 1 mole
This leftover reacts with MgO
But;
1 mole of MgO reacts with 2 moles of HCl
x moles of MgO reacts with 1 mole of HCl
Thus; x= 0.5 moles of MgO
1.26 x 10²⁴particles
Explanation:
Given parameters:
Number of moles of the compound = 2.1 moles
Unknown:
Number of particles contained in the compound = ?
Solution:
A mole can be defined as the amount of a substance that contains Avogadro's number of particles 6.02 x 10²³.
The particles mentioned here can be atoms, molecules, formula units, ions, electrons, protons, neutrons and so forth.
To solve for the number of moles:
Number of particles = number of moles x 6.02 x 10²³
Number of particles = 2.1 x 6.02 x 10²³ = 12.64 x 10²³ = 1.26 x 10²⁴particles
Learn more:
mole calculation brainly.com/question/1841136
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1) 0.89% m/v = 0.89 grams of NaCl / 100 ml of solution
=> 8.9 grams of NaCl in 1000 ml of solution = 8.9 grams of NaCl in 1 liter of solution
2) Molarity = M = number of moles of solute / liters of solution
=> calculate the number of moles of 8.9 grams of NaCl
3) molar mass of NaCl = 23.0 g /mol + 35.5 g/mol = 58.5 g / mol
4) number of moles of NaCl = mass / molar mass = 8.9 g / 58.5 g / mol = 0.152 mol
5) M = 0.152 mol NaCl / 1 liter solution = 0.152 M
Answer: 0.152 M
