Answer:
Empirical formula: BH3
Molecular Formula: B2H6
Explanation:
To solve the exercise, we need to know how many boron atoms and how many hydrogen atoms the compound has. We know that of the total weight of the compound, 78.14% correspond to boron and 21.86% to hydrogen. As the weight of the compound is between 27 g and 28 g, using the above percentages we can solve that the compound has between 21.1 g and 21.8 g of boron, and between 5.9 g and 6.1 g of hydrogen:
100% _____ 27 g
78.14% _____ x = 78.14% * 27g / 100% = 21.1 g boron
100% ______27 g
21.86% ______ x = 21.86% * 27g / 100% = 5.9 g hydrogen
100% _____ 28 g
78.14% _____ x = 78.14% * 28g / 100% = 21.8 g boron
100% _____ 28g
21.86% _____ x = 21.86% * 28g / 100% = 6.1 g hydrogen
So, if the atomic weight of boron is 10.8 g, there must be two boron atoms in the compound that sum 21.6 g. The weight of hydrogen is 1 g, so the compound must have six hydrogen atoms.
The molecular formula represents the real amount of atoms that form a compound. Therefore, the molecular formula of the compound is B2H6.
The empirical formula is the minimum expression that represents the proportion of atoms in a compound. For example, ethane has 2 carbon atoms and 6 hydrogen atoms, so its molecular formula is C2H6, however, its empirical formula is CH3. Therefore, the empirical formula of the boron compound is BH3.
Grams of oxygen are required to react with 13.0 grams of octane (C8H18) in the combustion of octane in gasoline is 45.5g
Octane is a hydrocarbon which burns in gasoline in presence of oxygen according to the given balanced chemical equation,
2C₈H₁₈ + 25O₂------> 16CO₂ + 18H₂0
Molar mass of octane = 114.23g/mol
Molar mass of Oxygen = 32g/mol
According to the stiochiometry of the balanced equation the mole ratio of Octane and Oxygen is 2:25
2 mole of octane needs 25 mole of oxygen
1 mole of octane needs 12.5 moleof oxygen
114.23g of octane needs 400g of oxygen
13g of octane needs 45.5g of oxygen
Mass of oxygen needed =45.5g
Hence, the Mass of oxygen needed is 45.5g for the combustion of octane in gasoline.
Learn more about Octane here, brainly.com/question/21268869
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An Ionic bond is the result of transfer of electrons between atoms
