2. Cooks use baking soda to make cakes light and fluffy. You might have used baking soda yourself. Baking soda is NaHCO3. A 0.1 M solution of baking soda in water has a [H+] of about 4.0 × 10–9. (You may prefer to think of the hydronium ion concentration, [H3O+], as 4.0 × 10–9.) Write the formula for the calculation of pH, and then show each step as you calculate the pH of a 0.1 M solution of baking soda.

Question

2.	Cooks use baking soda to make cakes light and fluffy. You might have used baking soda yourself. Baking soda is NaHCO3. A 0.1 M solution of baking soda in water has a [H+] of about 4.0 × 10–9. (You may prefer to think of the hydronium ion concentration, [H3O+], as 4.0 × 10–9.) Write the formula for the calculation of pH, and then show each step as you calculate the pH of a 0.1 M solution of baking soda.

aaronq · Answer

Since you already have the hydronium ion concentration, use the formula for pH:

 $\sf \Large  pH=-log[H_3O^+]$

anonymous · Answer

I got that part down...i am just not sure i'm plugging in mu numbers right...
ph= -log [4.0 x10^-9]???

aaronq · Answer

yeah, that's right

anonymous · Answer

I guess this is where I get stuck in my math

aaronq · Answer

all you gotta do is plug it into the calculator, there isn't an analytical way to solve logarithms

anonymous · Answer

then i must be plugging it in wrong with the 10^-9

aaronq · Answer

yeah, i think so try putting the negative exponent in brackets, like 10^(-9)

aaronq · Answer

and also put the whole number in brackets 

-log(number)

anonymous · Answer

guess it dont work on a regular calculator

aaronq · Answer

use this http://web2.0calc.com/

anonymous · Answer

ph=8.4?

anonymous · Answer

-8.4