## French Toast Number 27 Part B

KateCaldwell 1A
Posts: 43
Joined: Fri Apr 06, 2018 11:02 am

### French Toast Number 27 Part B

Part a has us solve for the volume, which I got correctly, but I keep getting the wrong pH value for part b. Can someone explain step by step how to do this? I did moles/volume the -log that value.

Chem_Mod
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### Re: French Toast Number 27 Part B

Metal oxides, like Na2O, form O2- in water. O2- reacts with water to form 2 moles of OH-. Therefore, you must make sure you double the molarity since each mole of Na2O yield 2 moles of OH-. Remember that you need hydronium and/or hydroxide ion concentrations to determine pH, not the concentration of the actual base or acid.

Gisselle Sainz 2F
Posts: 76
Joined: Wed Feb 21, 2018 3:00 am

### Re: French Toast Number 27 Part B

After doubling the molarity, I still didn't get the right answer.

Molarity= (.550/.21)= 2.62 x 2 = 5.24

and 14 minus the negative log of that doesn't result in the correct answer. I'm not sure what's wrong.

Lily Emerson 1I
Posts: 27
Joined: Fri Apr 06, 2018 11:02 am

### Re: French Toast Number 27 Part B

you just need to do 14-(-log(1.1)) since you already know that the concentration of the new mixture is .55 - just multiply that by 2 moles of HO- to get the concentration

Cindy Nguyen 1L
Posts: 48
Joined: Fri Apr 06, 2018 11:04 am

### Re: French Toast Number 27 Part B

Lily Emerson 1I wrote:you just need to do 14-(-log(1.1)) since you already know that the concentration of the new mixture is .55 - just multiply that by 2 moles of HO- to get the concentration

Where did you get 1.1 from?

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