3.65. The mole ratio from the balanced equation is 2 moles CO2 : 2 moles CO. 2.
Answer: (a) pH = 4.774, (b) pH = 4.811 and (c) pH = 4.681
Explanation: (a) pH of the buffer solution is calculated using Handerson equation:

pKa for acetic acid is 4.76. concentration of base and acid are given as 0.95M and 0.92M. Let's plug in the values in the equation and calculate the pH of starting buffer.

pH = 4.76 + 0.014
pH = 4.774
(b) When 0.040 mol of NaOH (strong base) are added to the buffer then it reacts with 0.040 mol of acetic acid and form 0.040 mol of sodium acetate.
Original buffer volume is 1.00 L. So, the original moles of sodium acetate will be 0.95 and acetic acid will be 0.92.
moles of acetic acid after addition of NaOH = 0.92 - 0.040 = 0.88
moles of sodium acetate after addition of NaOH = 0.95 + 0.040 = 0.99
Let's again plug in the values in the Handerson equation:

pH = 4.76 + 0.051
pH = 4.811
(c) When 0.100 mol of HCl are added then it reacts with exactly 0.100 moles of sodium acetate(base) and form 0.100 moles of acetic acid(acid).
so, new moles of acetic acid = 0.92 + 0.100 = 1.02
new moles of sodium acetate = 0.95 - 0.100 = 0.85
Let's plug in the values in the equation:

pH = 4.76 - 0.079
pH = 4.681
Answer: The answer has 7 significant figures
Explanation:
The addition of 190.5 and 42.1014 will give 232.6014. Counting the digits will give 7 significant figures.
Photosynthesis takes place in all ecosystems. Without it we would not be able to survive. Photosynthesis starts with plants. Plants are autotrophs which means they make their own food. During photosynthesis, plants take in sunlight, carbon dioxide (CO^2), and water during photosynthesis. They give off glucose and oxygen. Plants have chlorophyll in them which gives them their green color. Heterotrophs eat other living things to get energy. (If you want to go more into depth you can say this: Heterotrophs take in the glucose and oxygen. This is called cellular respiration. The products of cellular respiration are water, ATP (energy), and CO^2 which than leads you back to photosynthesis) Hope this helped! :)
B, I just took the test and the correct answer is b. Cheap doesn't always equal quality.