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3 years ago

11.

Chemistry

2 answers:

ohaa [14]3 years ago

6 0

Answer:

species originate through allopatric speciation:

Have a good day! :)

oksano4ka [1.4K]3 years ago

3 0

Answer:

species originate through allopatric speciation

Explanation:

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Why is salt an ionic bond? Why is salt an ionic bond?

yaroslaw [1]

: If you mean table salt i.e. sodium chloride. It is held together by ionic bonds between sodium (Na+) and chloride (Cl-) ions. The sodium ions have a positive charge and the chlorine ions have a negative charge. Since opposite charges attract, they form ionic bonds. Ionic bonds are nothing more than the attraction between positive and negative ions.

5 0

3 years ago

Chlorine is used to disinfect swimming pools. the accepted concentration for this purpose is 1.00 ppm chlorine, or 1.00 g of chl

frez [133]

The accepted concentration of chlorine is 1.00 ppm that is 1 gram of chlorine per million of water.

The volume of water is $2.29\times 10^{4} gal$ .

Since, 1 gal= 3785.41 mL

Thus, $2.29\times 10^{4} gal=2.29\times 10^{4}\times 3785.41 mL=8.66\times 10^{7}mL$

Density of water is 1 g/mL thus, mass of water will be $8.66\times 10^{7}g$ .

Since, 1 grams of chlorine → $10^{6}$ grams of water.

1 g of water → $10^{-6}$ g of chlorine and,

$8.66\times 10^{7}g$ of water →86.6 g of chlorine

Since, the solution is 9% chlorine by mass, the volume of solution will be:

$V=\frac{100}{9}\times 86.6 mL=9.62\times 10^{2} mL$

Thus, volume of chlorine solution is 9.62\times 10^{2} mL.

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3 years ago

If the black dot is sound, which direction is the sound in the picture moving? *

Tema [17]

Answer:

Left or up, either one of those

Explanation:

6 0

3 years ago

Read 2 more answers

Which of the following acids is the WEAKEST? The acid is followed by its Ka value.HF, 3.5 × 10^-4HNO2, 4.6 × 10^-4HCN, 4.9 × 10^

Mila [183]

Answer:

HCN

Explanation:

There are several factors that can tell us when an acid is stronger than another, which are the following:

1. The Polarity of the X - H Bond

2. Size of the X atom.

3. Charge on the acid.

4. Oxidation state of the central atom

5. Values of Ka and pKa.

From all of this factors, we can see that the exercise is already giving us values of Ka, and also we have different types of acid, not only with the form H - X

So, we will base the force of an acid by it's pKa value.

The pKa value which is calculated with the expression:

pKa = -logKa

pKa is a value that indicates how strong is the acid you are working with. This value can vary depending on factors such the charge of the acid. I f this charge can be easily distributed in resonance structures, the compound is more acidic, and therefore the pKa value is lower.

The lower the pKa, the more acidic the compound is.

So calculating the pKa on every structure we have:

HF: pKa = -log(3.5x10^-4) = 3.46

HNO2: pKa = -log(4.6x10^-4) = 3.34

HCN: pKa = -log(4.9x10^-10) = 9.31

HCOOH: pKa = -log(1.8x10^-4) = 3.74

HClO2: -log(1.1x10^-2) = 1.96

So according to all this values, we can conclude that the weakest acid is the HCN

4 0

3 years ago

A 1.25g sample of copper (cCu=0.386Jg∘C) is initially at a temperature of 25.0∘C. If the sample absorbs 87.4J of heat, what is i

professor190 [17]

Answer: Final temperature = 206∘C

Explanation:

Heat Energy is given as

q= mCΔT

ehere

q= Heat energy = 87.4J

m= mass=1.25g

C=specific heat c= 0.386Jg∘C) ,

ΔT = Change in temperate of which the final temperature= 25.0∘C

q= mCΔT

ΔT = q/mC

ΔT = 87.4/ 1.25 X 0.386=181.14∘C

But,

T final- T initial = ΔT

T final = T initial + ΔT

T final = 25.0∘C +181.14∘C=206.14∘C rounded to 206∘C

4 0

3 years ago