1.0 x 10^-3 x 65.38 = 0.0654 g Zn
6.9 x 10 to the power of 3 if I am not mistaken.
Answer: Option A) 25mL
Explanation:
Given that,
Original volume of gas (V1) = 75mL
Original temperature of gas (T1) = 450K
New volume V2 = ?
New temperature T2 = 150K
Since volume and temperature are given while pressure is held constant, apply the formula for Charle's law
V1/T1 = V2/T2
75mL/450K = V2/150K
To get the value of T2, cross multiply
75mL x 150K = 450K x V2
11250mL•K = 450K•V2
Divide both sides by 450K
11250mL•K / 450K = 450K•V2/450K
25mL = V2
Thus, the new volume of the gas is 25mL
Answer. Answer: Scientists study how things work, while engineers create new things
Answer:
The pH of the buffer solution = 8.05
Explanation:
Using the Henderson - Hasselbalch equation;
pH = pKa₂ + log ( [HPO₄²-]/[H₂PO4⁻]
where pKa₂ = -log (Ka₂) = -log ( 6.1 * 10⁻⁸) = 7.21
Concentration of OH⁻ added = 0.069 M (i.e. 0.069 mol/L)
[H₂PO4⁻] after addition of OH⁻ = 0.165 - 0.069 = 0.096 M
[HPO₄²-] after addition of OH⁻ = 0.594 + 0.069 = 0.663 M
Therefore,
pH = 7.21 + log (0.663 / 0.096)
pH = 7.21 + 0.84
pH = 8.05
