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Answer is: <span>1.6×10−9m.
</span><span>This is buffer solution, so
use Henderson–Hasselbalch equation:
</span>V(solution) = 150 mL + 150 mL = 300 mL ÷ 1000 mL/L = 0.3 L.
c(HCN) = ck = 0.15 L · 0.1 M / 0.3 L = 0.05 M.
c(NaCN) = cs = 0.15 L · 0.03 M / 0.3 M = 0.015 M.
[H⁺] = Ka · (ck/cs).
[H⁺] = 4.9·10⁻¹⁰ · (0.05 M ÷ 0.015 M).
[H⁺] = 1.63·10⁻⁹ M.
The answer is 4.45 × 10²⁴ units.
To calculate this, we will use Avogadro's number which is the number of units (atoms, molecules) in 1 mole of substance:
6.02 × 10²³ units per 1 mole
So, we need a proportion:
If 6.02 × 10²³ units are in 1 mole, how many units will be in 7.40 moles:
6.02 × 10²³ units : 1 mole = x : 7.40 moles
After crossing the products:
1 mole * x = 7.40 moles * 6.02 × 10²³ units
x = 7.40 * 6.02 × 10²³ units
x = 44.5 × 10²³ units = 4.45× 10²⁴ unit
Answer:
0.25 moles
Explanation:
The molar mass of NaOH is 40 g/mol.
This equals 0.25 moles