We know that to relate solutions of with the factors of molarity and volume, we can use the equation:

**
NOTE: The volume as indicated in this question is defined in L, not mL, so that conversion must be made. However it is 1000 mL = 1 L.
So now we can assign values to these variables. Let us say that the 18 M

is the left side of the equation. Then we have:

We can then solve for

:

and

or

We now know that the total amount of volume of the 4.35 M solution will be
210 mL. This is assuming that the entirety of the 50 mL of 18 M is used and the rest (160 mL) of water is then added.
Each mole of Ca(OH)₂ will produce 2 moles of OH- ions
Each mole of OH- ions will require one mole of H+ ions
Thus,
moles of OH- ions = moles of H+ ions = 2 x 0.3
moles of H+ ions required = 0.6
Each mole of HCl will produce one mole of H+ ions
Moles of HCl = moles of H+ ions
Moles of HCl = 0.6
Answer:
1,806,000,000,000,000,000,000,000 atoms.
Explanation:
1 mol of anything is 6.022*10^23 units
1 mol carbon atoms = 6.022*10^23 carbon atoms
3 mol carbon atoms = 3*6.022*10^23 = 1.8*10^24 atoms
Correctly - your answer should have only 1 significant digit: 2 * 10^24 atoms.