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
Answer:D and C sorry if im wrong
Explanation:
Answer:
empirical formula is C7H3NCl2
Explanation:
too much work too explain and im lazy
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of hydrogen chloride would be produced by this reaction if 3.16 L of chlorine were consumed at STP.
Be sure your answer has the correct number of significant digits.
Answer: Thus volume of carbon tetrachloride that would be produced is 0.788 L
Explanation:
According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)
V = Volume of gas = 3.16 L
n = number of moles = ?
R = gas constant =
T =temperature =



According to stoichiometry:
4 moles of chlorine produces = 1 mole of carbon tetrachloride
Thus 0.141 moles of methane produces =
moles of carbon tetrachloride
volume of carbon tetrachloride =
Thus volume of carbon tetrachloride that would be produced is 0.788 L