Answer:
1.60.
Explanation:
- The no. of millimoles of HCl = MV = (0.15 M)(20.0 mL) = 3.0 mmol.
- The no. of millimoles of KOH = MV = (0.10 M)(20.0 mL) = 2.0 mmol.
<em>Since the no. of millimoles of HCl is larger than that of KOH. The solution is acidic.</em>
<em></em>
∴ M of remaining HCl [H⁺] remaining = (NV)HCl - (NV)KOH/V total = (3.0 mmol) - (2.0 mmol) / (40.0 mL) = 0.025 M.
∵ pH = - log[H⁺]
<em>∴ pH = - log[H⁺] </em>= - log(0.025) = <em>1.602 ≅ 1.60.</em>
Answer:
The coefficients in order are 2, 1, 1
Explanation:
Each side of the reaction needs to have the same number of each element due to conservation of matter.
First I looked at what was uneven, notice there are 2 Na on the left side and 4 Na on the left. The easiest way to fix that is to add a 2 on the Na2HPO4:
2(Na2HPO4)--> Na4P2O7 + H2O
Next take count of each element on both sides to see if the 2 balanced everything:
On the left there are 4 Na, 2 H, 2 P, and 8 O
On the right there are 4 Na, 2 H, 2 P, and 8 O
Since both sides match, you are done!
Answer:
mg atom have 12 election and mg ion have 10 election
