Answer:
(3) 5.36
Explanation:
Since this is a titration of a weak acid before reaching equivalence point, we will have effectively a buffer solution. Then we can use the Henderson-Hasselbalch equation to answer this question.
The reaction is:
HAc + NaOH ⇒ NaAc + H₂O
V NaOH = 40 mL x 1 L/1000 mL = 0.040 L
mol NaOH reacted with HAc = 0.040 L x 0.05 mol/L = 0.002 mol
mol HAC originally present = 0.050 L x 0.05 mol/L = 0.0025 mol
mol HAc left after reaction = 0.0025 - 0.002 = 0.0005
Now that we have calculated the quantities of the weak acid and its conjugate base in the buffer, we just plug the values into the equation
pH = pKa + log ((Ac⁻)/(HAc))
(Notice we do not have to calculate the molarities of Ac⁻ and HAc because the volumes cancel in the quotient)
pH = -log (1.75 x 10⁻⁵) + log (0.002/0.0005) = 5.36
THe answer is 5.36
Answer:
I believe it's A generally increases may be wrong
According to this formula, when:
ΔG = ΔH - T*ΔS
when the reaction is thermodynamically spontaneous ΔG < 0
∴ ΔH - T* ΔS = 0
∴T*ΔS = ΔH
∴ T = ΔH / ΔS
when we have:
ΔH = -70KJ
and ΔS = -0.4 KJ/K
So by substitution:
T = -70KJ /- 0.4
= 175 K
∴the certain temperature below which the reaction will be thermodynamically spontaneous is 175 K
Answer:
Mass = 15.13 g
Explanation:
Given data:
Number of atoms of hydrogen = 8.11×10²³
Mass of ammonia formed = ?
Solution:
Chemical equation:
3H₂ + N₂ → 2NH₃
Number of moles of hydrogen:
1 mole contain 6.022× 10²³ atoms
8.11×10²³ atoms × 1 mol / 6.022× 10²³ atoms
1.35 mol
Now we will compare the moles of hydrogen and ammonia:
H₂ : NH₃
3 : 2
1.35 : 2/3×1.35 = 0.89 mol
Mass of ammonia:
Mass = number of moles × molar mass
Mass = 0.89 mol × 17 g/mol
Mass = 15.13 g
Answer:
Matter cannot be created destroyed
Explanation
Matter can change form through physical and chemical changes, but through any of these changes, matter is conserved. The same amount of matter exists before and after the change—none is created or destroyed. This concept is called the Law of Conservation of Mass.
