<u>Answer:</u> The pH of the buffer is 4.61
<u>Explanation:</u>
To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:
![pH=pK_a+\log(\frac{[\text{conjuagate base}]}{[\text{acid}]})](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%28%5Cfrac%7B%5B%5Ctext%7Bconjuagate%20base%7D%5D%7D%7B%5B%5Ctext%7Bacid%7D%5D%7D%29)
We are given:
= negative logarithm of acid dissociation constant of weak acid = 4.70
= moles of conjugate base = 3.25 moles
= Moles of acid = 4.00 moles
pH = ?
Putting values in above equation, we get:

Hence, the pH of the buffer is 4.61
Answer:
0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.
Explanation:
The balanced reaction is:
4 Fe + 3 O₂ → 2 Fe₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
- Fe: 4 moles
- O₂: 3 moles
- Fe₂O₃: 2 moles
You can apply the following rule of three: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, 0.15 moles of Fe produce how many moles of Fe₂O₃?

moles of Fe₂O₃= 0.075
<u><em>0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.</em></u>
<u>Answer:</u> The volume of water required is 398 mL
<u>Explanation:</u>
To calculate the molarity of solution, we use the equation:

We are given:
Mass of solute (manganese (II) nitrate tetrahydrate) = 16 g
Molar mass of manganese (II) nitrate tetrahydrate = 251 g/mol
Molarity of solution = 0.16 M
Putting values in above equation, we get:

Hence, the volume of water required is 398 mL
Explanation:
the experiment conducted is the student adds sugar to a cup of iced tea and a cup of hot tea. She notices that the time needed for the sugar to dissolve in each cup is different. She thinks this has something to do with the temperature of the tea
hypothesis: If the student puts the sugar in both glasses of tea, then the sugar in the hot tea should dissolve quicker.