Question is incomplete, complete question is;
A 34.8 mL solution of
(aq) of an unknown concentration was titrated with 0.15 M of NaOH(aq).

If it takes 20.4 mL of NaOH(aq) to reach the equivalence point of the titration, what is the molarity of
? For your answer, only type in the numerical value with two significant figures. Do NOT include the unit.
Answer:
0.044 M is the molarity of
(aq).
Explanation:
The reaction taking place here is in between acid and base which means that it is a neutralization reaction .
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

0.044 M is the molarity of
(aq).
Answer: 26.7 moles
Explanation: 
As can be seen from the balanced chemical equation 2 moles of hydrogen combine with 1 mole of oxygen to give two moles of water.
1 mole of oxygen give = 2 moles of water.
Thus 13.35 moles of oxygen give=
of water.
Answer:
Composition of the mixture:
%
%
Composition of the vapor mixture:
%
%
Explanation:
If the ideal solution model is assumed, and the vapor phase is modeled as an ideal gas, the vapor pressure of a binary mixture with
and
molar fractions can be calculated as:

Where
and
are the vapor pressures of the pure compounds. A substance boils when its vapor pressure is equal to the pressure under it is; so it boils when
. When the pressure is 0.60 atm, the vapor pressure has to be the same if the mixture is boiling, so:

With the same assumptions, the vapor mixture may obey to the equation:
, where P is the total pressure and y is the fraction in the vapor phase, so:
%
The fractions of B can be calculated according to the fact that the sum of the molar fractions is equal to 1.
Answer:
<em>Mass number = protons + neutron</em>
<em />
<em>The mass number of an element is the sum of the protons and neutrons. The number of neutrons for a given element is the only number that can change and still have the identity of the element stay the same, (because the atomic number is the number of protons).
</em>
<em>
</em>
<em>In this case the mass number would be 11</em>
HOPE THIS HELPS!!!
Unit conversion help you in chemistry more than anything know that 1mi=1.60934km
100x1.60934 = 160.934km