Answer:
pH = 3.3
Explanation:
Buffer solutions minimize changes in pH when quantities of acid or base are added into the mix. The typical buffer composition is a weak electrolyte (wk acid or weak base) plus the salt of the weak electrolyte. On addition of acid or base to the buffer solution, the solution chemistry functions to remove the acid or base by reacting with the components of the buffer to shift the equilibrium of the weak electrolyte left or right to remove the excess hydronium ions or hydroxide ions is a way that results in very little change in pH of the system. One should note that buffer solutions do not prevent changes in pH but minimize changes in pH. If enough acid or base is added the buffer chemistry can be destroyed.
In this problem, the weak electrolyte is HNO₂(aq) and the salt is KNO₂(aq). In equation, the buffer solution is 0.55M HNO₂ ⇄ H⁺ + 0.75M KNO₂⁻ . The potassium ion is a spectator ion and does not enter into determination of the pH of the solution. The object is to determine the hydronium ion concentration (H⁺) and apply to the expression pH = -log[H⁺].
Solution using the I.C.E. table:
HNO₂ ⇄ H⁺ + KNO₂⁻
C(i) 0.55M 0M 0.75M
ΔC -x +x +x
C(eq) 0.55M - x x 0.75M + x b/c [HNO₂] / Ka > 100, the x can be
dropped giving ...
≅0.55M x ≅0.75M
Ka = [H⁺][NO₂⁻]/[HNO₂] => [H⁺] = Ka · [HNO₂]/[NO₂⁻]
=> [H⁺] = 6.80x010⁻⁴(0.55) / (0.75) = 4.99 x 10⁻⁴M
pH = -log[H⁺] = -log(4.99 x 10⁻⁴) -(-3.3) = 3.3
Solution using the Henderson-Hasselbalch Equation:
pH = pKa + log[Base]/[Acid] = -log(Ka) + log[Base]/[Acid]
= -log(6.8 x 10⁻⁴) + log[(0.75M)/(0.55M)]
= -(-3.17) + 0.14 = 3.17 + 0.14 = 3.31 ≅ 3.3
Answer:
28.497 cm3
Explanation:
Formula
D=m/v
Given data:
density = 19.3g/cm3
mass = 550 g
Now we will put the values in formula:
V=m/d
V=550 g/ 19.3 g/cm3 = 28.497 cm3
So the volume of gold is 28.497 cm3.
Answer:
Rate = k . [B]² . [C]
Explanation:
The dependence of the reaction rate on the concentration of the reactants is given by the reaction order of each one, as shown in the rate equation.
![Rate=k.[A]^{x} .[B]^{y} .[C]^{z}](https://tex.z-dn.net/?f=Rate%3Dk.%5BA%5D%5E%7Bx%7D%20.%5BB%5D%5E%7By%7D%20.%5BC%5D%5E%7Bz%7D)
where,
k is the rate constant
x, y, z are the reaction orders.
- <em>The rate of reaction is not affected by changing the concentration of species A.</em> This means that the reaction order for A is x = 0 since when its concentration changes, the rate stays the same.
- <em>Leaving all other factors identical, doubling the concentration of species B increases the rate by a factor of 4.</em> This means that the reaction order for B is y = 2, so when the concentration is doubled, the new rate is 2² = 4 times the initial rate.
- The rate of the reaction is linearly dependent on the concentration of C. This means that the reaction order for C is z = 1, that is, a linear dependence.
All in all, the rate equation is:
Rate = k . [B]² . [C]
A fusion reaction can be regarded as the type of reaction that occurs where two lighter elements come together in a type of reaction giving rise to a heavier/more massive element.
A fusion reaction always creates a more massive atomic nucleus (option c).
When the two lighter nuclei comes together in a reaction, a more heavier/massive nucleus is formed but its mass will still be less than the combined mass of the two reactant nuclei.
This also indicates that the left over mass may have been released as energy.
Learn more: brainly.com/question/18175586
Answer: option B. closer to oxygen in the case of CO2
Explanation:
