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Ethanol is found to have a relative molecular mass of 46. If its molecular formula is C2HxOH. What is the value of X in the formula?

User Krisha
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1 Answer

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16 votes

Answer:

The value of x in ethanol is 5

Step-by-step explanation:

Given molar mass, you can subtract the molar masses of different elements present to find the missing amount of hydrogen; in other words:
Carbon*2 + Hydrogen*x + Oxygen*1 + Hydrogen*1 = 46
Molar mass carbon = 12.01
Molar mass hydrogen = 1
Molar mass oxygen = 16
12.01*2 g/mol + 1*x g/mol + 16*1 g/mol + 1*1 g/mol = 46 g/mol
Subtracting all knowns from the current molar mass gives
46 - 41.02 = 4.98

This means that x amounts of hydrogen has a molar mass of 4.98, or roughly just 5. Since each hydrogen has a molar mass of one, that means that there are 5 hydrogens missing and the complete molecular formula is C2H5OH

User Falguni
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