How do you use the changes in the phase of water to keep you cool?

An intertidal area is one where the ocean meets the land.

Nikolay [14]

Answer:

T or True

Explanation:

The intertidal zone is any place or area where the ocean meets land, also known as shorelines or coastlines. The ecosystems found in these area experience lots of changes. Just think, whenever the tides are low, the area is exposed to air and the sun, but during low tide, it is submerged underwater.

8 0

2 years ago

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Calculate the number of moles equivalent to 12.7 gram of iodine molecule

Alexus [3.1K]

$\LARGE{ \boxed{ \purple{ \rm{Answer}}}}$

☃️ Chemical formulae ➝ $\sf{I_2}$

How to find?

For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

$\boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}$

Solution:

❍ Molecular weight of $\sf{I_2}$

= 2 × 126.90

= 253.80

= 254 (approx.)

❍ Given weight: 12.7

Then, no. of moles,

⇛ No. of moles = 12.7 / 254

⇛ No. of moles = 0.05 moles

⚘ No. of moles of Iodine molecule in the given weight = 0.05 moles

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6 0

3 years ago

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Is the bond formed between each pair of atoms pure covalent (a.k.a. nonpolar covalent), polar covalent, or ionic?

swat32

Answer:

So, look up for electronegativity table

There's a continuum for deciding whether the bond is non-polar, polar, or ionic

If electronegativity difference is less than 0.4 it's non-polar

Explanation:

Pls vote my answer as brainliest

7 0

3 years ago

A diprotic acid, H₂A, has Ka1 = 3.4 × 10⁻⁴ and Ka2 = 6.7 × 10⁻⁹. What is the pH of a 0.18 M solution of H₂A?

Tcecarenko [31]

Answer:

pH = 2.10

Explanation:

We name an acid as diprotic because it can release two protons:

H₂A + H₂O ⇄ H₃O⁺ + HA⁻ Ka₁

HA⁻ + H₂O ⇄ H₃O⁺ + A⁻² Ka₂

We propose the mass balance:

Analytical concentration = [H₂A] + [HA⁻] + [A⁻²]

As Ka₂ is so small, we avoid the [A⁻²] so:

0.18 M = [H₂A] + [HA⁻]

But we can not avoid the HA⁻, because the Ka₁. Ka₁'s expression is:

Ka₁ = [H₃O⁺] . [HA⁻] / [H₂A]

We propose the charge balance:

[H₃O⁺] = [HA⁻] + [A⁻²] + [OH⁻]

As we did not consider the A⁻², we can miss the term and if

Kw = H⁺ . OH⁻

We replace Kw/H⁺ = OH⁻. So the new equation is:

[H₃O⁺] = [HA⁻] + Kw / [H₃O⁺]

The acid is so concentrated, so we can avoid the term with the Kw, so:

[H₃O⁺] = [HA⁻]

In the mass balance we would have:

0.18 M = [H₂A]

We replace at Ka₁

Ka₁ = [H₃O⁺] . [HA⁻] / [H₂A]

Ka1 . 0.18 / [H₃O⁺] = [HA⁻]

We replace at the charge balance:

[H₃O⁺] = Ka1 . 0.18 / [H₃O⁺]

[H₃O⁺]² = 3.4×10⁻⁴ . 0.18

[H₃O⁺] = √(3.4×10⁻⁴ . 0.18)

[H₃O⁺] = 7.82×10⁻³

- log [H₃O⁺] = pH → - log 7.82×10⁻³

pH = 2.10

5 0

3 years ago

Determine whether each cation is acidic or pH-neutral. For the cations that are acidic, write an equation that shows how the cat

Anton [14]

THE COMPLETE QUESTION IS:

Determine whether each cation is acidic or pH-neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid . a. NH+4 b. Na+ c. Co3+ d. CH2NH+3

Answer:

a. Acidic

b. neutral

c. Acidic

d. Acidic

Explanation:

a. NH4+ + H2O <==> NH3 + H3O+ (NH4+ is a conjugate acid of a weak base. Therefore it is acidic)

b. Neutral. Na+ is a cation of a strong base. Therefore it's pH is neutral.

c. Co(H2O)6³+ + H2O <==>CoH2O5(OH)²+ + H3O+

(Therefore Co+ is a weak acid since hydronium ion is formed.)

d. CH2NH3+ is a conjugate acid of a weak base. Therefore it is acidic.

6 0

3 years ago