If 10.0 mL of 1.0M HCl is added to 90 mL water, what is he concentration of the new solution?

What is the pH of this solution?
If the solution is titrated by 0.500M
Ca(OH)2, how much volume (ml) of NaOH necessary? Need help pls.

sorry the chemical reaction is:

Ca(OH)2 (aq) + 2HCl(aq)= 2H2O(l)+CaCl2(aq)

Who knows what the new concn is? This is a fairy tale problem because it ASSUMES that the volumes are additive. They are not; however they are very close to it in this case so we will assume the total volume is 100 mL

Use c1v1 = c2v2
c = concn
v = volume

1.0M x 10mL = c2*100
C2 = (1.0 x 10/100) = ?

pH = -log(H^+)

mols HCl = M x L = ?
Convert mols HCl to mols Ca(OH)2. That's mols Ca(OH)2 = 1/2 mols HCl (from the coefficients in the balanced equation). Then
M Ca(OH)2 = mols Ca(OH)2/L Ca(OH)2. You know mols and M, solve for L and convert to mL).

To find the concentration of the new solution, we need to use the equation for dilution:

C1V1 = C2V2

where C1 and V1 are the initial concentration and volume, and C2 and V2 are the final concentration and volume.

In this case, the initial concentration (C1) is 1.0M and the initial volume (V1) is 10.0 mL. The final volume (V2) is the sum of the initial volume and water volume, which is 10.0 mL + 90.0 mL = 100.0 mL.

Plugging these values into the equation, we have:

(1.0M)(10.0 mL) = C2(100.0 mL)

Solving for C2, we get:

C2 = (1.0M)(10.0 mL) / 100.0 mL = 0.1M

So, the concentration of the new solution is 0.1M.

To find the pH of this solution, we need to know the concentration of H+ ions. Since HCl is a strong acid, it dissociates completely into H+ and Cl- ions.

Therefore, the concentration of H+ ions in the solution is equal to the concentration of HCl, which is 0.1M.

To calculate the pH, we can use the equation:

pH = -log[H+]

Substituting the concentration of H+ ions, we have:

pH = -log(0.1) = 1

So, the pH of this solution is 1.

Now, if this solution is titrated by 0.500M Ca(OH)2, you're asking how much volume (in mL) of NaOH is necessary. However, it seems there is an error in the question. We are given the concentration of Ca(OH)2, not NaOH.

If you provide the concentration of NaOH or any other relevant information, I would be happy to help you with the calculation.