Answer:
0.0125mol
Explanation:
Molarity (M) = number of moles (n) ÷ volume (V)
n = Molarity × Volume
According to this question, a 0.05M solution contains 250 mL of NaOH. The volume in litres is as follows:
1000mL = 1L
250mL = 250/1000
= 0.250L
n = 0.05 × 0.250
n = 0.0125
The number of moles of NaOH is 0.0125mol.
The volume of the 0.279 M Ca(OH)₂ solution required to neutralize 24.5 mL of 0.390 M H₃PO₄ is 51.4 mL
<h3>Balanced equation </h3>
2H₃PO₄ + 3Ca(OH)₂ —> Ca₃(PO₄)₂ + 6H₂O
From the balanced equation above,
- The mole ratio of the acid, H₃PO₄ (nA) = 2
- The mole ratio of the base, Ca(OH)₂ (nB) = 3
<h3>How to determine the volume of Ca(OH)₂ </h3>
- Molarity of acid, H₃PO₄ (Ma) = 0.390 M
- Volume of acid, H₃PO₄ (Va) = 24.5 mL
- Molarity of base, Ca(OH)₂ (Mb) = 0.279 M
- Volume of base, Ca(OH)₂ (Vb) =?
MaVa / MbVb = nA / nB
(0.39 × 24.5) / (0.279 × Vb) = 2/3
9.555 / (0.279 × Vb) = 2/3
Cross multiply
2 × 0.279 × Vb = 9.555 × 3
0.558 × Vb = 28.665
Divide both side by 0.558
Vb = 28.665 / 0.558
Vb = 51.4 mL
Thus, the volume of the Ca(OH)₂ solution needed is 51.4 mL
Learn more about titration:
brainly.com/question/14356286
Is this a multi choice question?????????????????????
Answer:
n = 6.06 x 
mol
Explanation:
n =?
m = 3.06 x 10-³ g
M (H5) = 5 x 1.01 (Since we only want hydrogen)
Atomic mass of C = 12.01
Atomic mass of H is 1,01, etc.
Having this data, we can use the Molar mass formula and change it so we can know the quantity of matter (n) in moles, and we just replace it.
M = 
⇔ n = 
⇔ n = 
⇔ n = 6.06 x mol
Note: The numbers I've used may be different from yours, by a small difference. I don't know if it's the case, but hope it helped.
