What percentage of the mass of hydrofluoric acid (HF) is contributed by hydrogen?
1 answer:
This problem is asking for the percent by mass of hydrogen in hydrofluoric acid. At the end, the answer turns out to be D. 5% as shown below:
<h3>Percent compositions:</h3>In chemistry, percent compositions are used for us to know the relative amount of a specific element in a compound. In order to do so for hydrogen, we use the following formula, which can also be applied to any other element in a given compound:
Where stands for the atomic mass of hydrogen and
for the molar mass of hydrofluoric acid. In such a way, we plug in the atomic masses of hydrogen (1.01 g/mol) and fluorine (19.0 g/mol) to obtain:
Learn more about percent compositions: brainly.com/question/12247957
You might be interested in
Answer:
Lathanum .
Atomic number = 57
Symbol = La
Atomic weight = 138.9
No of energy orbitals = 6
Electronic configuration
Answer: 72.4 kJ/mol
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
where,
n = number of moles
(as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
Therefore, the heat of formation of propane is 72.4 kJ/mol
Answer: 281 hours
Explanation:-
1 electron carry charge=
1 mole of electrons contain= electrons
Thus 1 mole of electrons carry charge=
of electricity deposits 1 mole or 63.5 g of copper
0.0635 kg of copper is deposited by 193000 Coloumb
11.5 kg of copper is deposited by= Coloumb
where Q= quantity of electricity in coloumbs = 34952756 C
I = current in amperes = 34.5 A
t= time in seconds = ?
Thus it will take 281 hours to plate 11.5 kg of copper onto the cathode if the current passed through the cell is held constant at 34.5 A.