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3 years ago

Question 21 of 25

Chemistry

1 answer:

hammer [34]3 years ago

8 0

Answer: Mg and O

Explanation: just took the test. Trust

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Which is most likely an effect of long-term environmental changes

Alina [70]

Answer:

adaptation

extinction

speciation

Explanation:

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3 years ago

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Water ionizes by the equationH2O(l)⇌H+(aq)+OH−(aq)The extent of the reaction is small in pure water and dilute aqueous solutions

tia_tia [17]

Explanation:

$H_2O(l)\rightleftharpoons H^+(aq)+OH^-(aq)$

The value of $K_w$ :

$K_w=[H^+][OH^-]$

a. pOH = 3.51

The sum of pH and pOH is equal to 14.

pH + pOH = 14 (at 25°C)

pH = 14 - 3.51 = 10.49

The pH of the solution is defined as negative logarithm of hydrogen ion concentration in solution.

$pH=-\log[H^+]$

$10.49=-\log[H^+]$

$[H^+]=3.2\times 10^{-11}$

$3.2\times 10^{-11} M$ is the $H^+$ concentration for an aqueous solution with pOH = 3.51 at 25°C.

At a certain temperature, the pH of a neutral solution is 7.56.

Neutral solution means that concentration of hydrogen ion and hydroxide ions are equal.

$[H^+]=[OH^-]$

$7.56=-\log[H^+]$

$[H^+]=2.754\times 10^{-8} M$

The value of $K_w$ at at this temperature:

$K_w=[H^+][OH^-]$

$K_w=[H^+][H^+]$

$K_w=(2.754\times 10^{-8})^2=7.6\times 10^{-16}$

The value of $K_w$ at at this temperature is $7.6\times 10^{-16}$ .

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4 years ago

With proper illustration, show the bond<br>formation in CO2 and what type of bond is involved

Ipatiy [6.2K]

Answer:

ㅍㅇㅎㅇㅎㅅㅇㅎ젖ㄴㄹ자

Explanation:

ㅔ볺ㄴㅍㅍ짜븐ㅍㄴㅎㄴ

4 0

4 years ago

Oxygen gas can be prepared by heating potassium chlorate according to the following equation:

Cerrena [4.2K]

Moles KClO₃ = 0.239

<h3>Further explanation</h3>

Given

Reaction

2KClO₃(s) ⇒2KCl(s) + 3O₂(g)

P water = 23.8 mmHg

P tot = 758 mmHg

V = 9.07 L

T = 25 + 273 = 298 K

Required

moles of KClO₃

Solution

P tot = P O₂ + P water

P O₂ = P tot - P water

P O₂ = 758 - 23.8

P O₂ = 734.2 mmHg = 0.966 atm

moles O₂ :

n = PV/RT

n = 0.966 x 9.07 / 0.082 x 298

n = 0.358

From equation, mol ratio KClO₃ : O₂ = 2 : 3, so mol KClO₃ :

= 2/3 x mol O₂

= 2/3 x 0.358

= 0.239

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3 years ago

How is the separation of dna like a zipper

Sedbober [7]

The two strands must be separated like the two sides of a zipper, by breaking the weak hydrogen bonds that link the paired bases.

<u>Explanation:</u>

A double helix structure formed by two polypeptide chains is separated like the two sides of a zipper. A zipper is formed by breaking the weak hydrogen bonds that link the paired bases. During replication, an enzyme "Helicase" travels down the DNA and splits the chain and it forms 2 separate strands.

The two DNA strand which has the same sequence must be separated like the two sides of a zipper by breaking weak hydrogen bases. During base pair-rule, the strand are unzipped and each strands is copied.

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3 years ago