M=70.0 g
p=0.70 g/mL
v=m/p
v=70.0/0.70=100.00 mL
Explanation:tr
a) Molar mass of HF = 20 g/mol
Atomic mass of hydrogen = 1 g/mol
Atomic mass of fluorine = 19 g/mol
Percentage of an element in a compound:

Percentage of fluorine:

Percentage of hydrogen:

b) Mass of hydrogen in 50 grams of HF sample.
Moles of HF = 
1 mole of HF has 1 mole of hydrogen atom.
Then 2.5 moles of HF will have:
of hydrogen atom.
Mass of 2.5 moles of hydrogen atom:
1 g/mol × 2.5 mol = 2.5 g
2.5 grams of hydrogen would be present in a 50 g sample of this compound.
c) As we solved in part (a) that HF molecules has 5% of hydrogen by mass.
Then mass of hydrogen in 50 grams of HF compound we will have :
5% of 50 grams of HF = 
An acid has several definitions one would be that it is a proton donor and an electron donor. Also, it said to produce an H+ ion when in solution. For nitric acid in solution, it dissociates into ions which are NO- ions and H+ ions. So, it must be an acid. It has a dissociation reaction:
HNO3 = H+ + NO3-
The STP stands for standard temperature and pressure which means in a condition where the temperature is 273.15K and the pressure is 0.986atm. In STP, an ideal gas will have a volume 22.4 liters for every mol of gas. Then, the amount of molecule of the <span>33.6 l of chlorine gas (Cl2) would be:
volume of gas/ number of mol= 22.4l/mol
</span>33.6l/ number of mol= 22.4l/mol
<span>number of mol= 33.6l / (22.4 liters/mol)= 1.5 moles
The mass of the gas would be: 1.5 moles * </span><span>70.906 </span>g/mol= 106.359 grams