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3 years ago

Consider the following data on some weak acids and weak bases

Chemistry

1 answer:

SpyIntel [72]3 years ago

6 0

Answer:

b < c < a < d

Explanation:

The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.

The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.

Ka Acetic acid = 1.8x10-5

Ka HCN = 1.9x10-10

Kb pyridine = 1.7x10-9

Kb NH3 = 1.8x10-5

NH4Br is the conjugate base of a weak base. That means is a strong acid.

NH4Br has the lowest pH

NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral

The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.

The rank is:

NH4Br < NaBr < NaCH3CO2 < KCN

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given a k value of 0.43 for the following aqueous equilibrium suppose sample z is placed into water such that its original conce

serious [3.7K]

Answer:

Less than 0.033 M:

$[Z]_{eq}=2.4x10^{-3}M$

Explanation:

Hello,

In this case, the described equilibrium is:

$2A+B\rightarrow 2Z$

Thus, the law of mass action is:

$K=\frac{[Z]^2}{[A]^2[B]}=0.43$

Nevertheless, given the initial concentration of Z that is 0.033 M, we should invert the equilibrium since the reaction will move leftwards:

$\frac{1}{K}=\frac{[A]^2[B]}{[Z]^2}=\frac{1}{0.43}=2.33$

Know, by introducing the change $x$ due to the reaction extent, we can write:

$2.33=\frac{(2x)^2*x}{(0.033-2x)^2}$

Which has the following solution:

$x_1=2.29M\\x_2=0.0181M\\x_3=0.0153M$

But the correct solution is $x_3=0.0152M$ since the other solutions make the equilibrium concentration of Z negative which is not possible. In such a way, its concentration at equilibrium is:

$[Z]_{eq}=0.033M-2(0.0153M)$

$[Z]_{eq}=2.4x10^{-3}M$

Which is clearly less than 0.033 M since the addition of a product shift the reaction leftwards in order to reestablish equilibrium (Le Chatelier's principle).

Regards.

6 0

3 years ago

select all that apply... Which of the following have energy stored as chemical energy? nuclear...petroleum...biomass...geotherma

d1i1m1o1n [39]

<span>Petroleum and biomass are burned in combustion reactions, which liberate energy stored in chemical bonds. This is chemical energy. In contrast, nuclear energy comes from the conversion of mass into energy when an nuclear reaction occurs. Geothermal energy comes directly from heat sources underground, with no chemical or nuclear reactions.</span>

6 0

3 years ago

How<br> many<br> molecules are in 8.55x10-15 moles of a substance

solniwko [45]

Answer:

Know this

1mole of a substance contains 6.022x10²³molecules

Now

8.55x10^-15moles x 6.022x10²³molecules/1mole

=5.15x10^9molecules.

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3 years ago

Definition of the word derived?

FromTheMoon [43]

Answer:

obtain something from (a specified source).

Explanation:

6 0

4 years ago

Read 2 more answers

How many grams S03<br> are needed to make 400g<br> H₂So4 in 49%

NemiM [27]

160 g of SO3 are needed to make 400 g of 49% H2SO4.

<h3>How many grams of SO3 are required to prepare 400 g of 49% H2SO4?</h3>

The equation of the reaction for the formation of H2SO4 from SO3 is given below as follows:

$SO_{3} + H_{2}O \rightarrow H_{2}SO_{4}$

1 mole of SO3 produces 1 mole of H2SO4

Molar mass of SO3 = 80 g/mol

Molar mass of H2SO4 = 98 g/mol

80 g of SO3 are required to produce 98 og 100%H2SO4

mass of SO3 required to produce 400 g of 100 %H2SO4 = 80/98 × 400 = 326.5 g of SO3

Mass of SO3 required to produce 49% of 400 g H2SO4 = 326.5 × 49% = 160 g

Therefore, 160 g of SO3 are needed to make 400 g of 49% H2SO4.

Learn more about mass and moles at: brainly.com/question/15374113

#SPJ1

7 0

2 years ago