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3 years ago

PLZ HELP ME!!!! I will give brainlist

Chemistry

1 answer:

svetoff [14.1K]3 years ago

7 0

Answer:

For 1, your answer is b. absorbs, endothermic. For 2, your answer is a. a solution becomes more dilute.

Explanation:

I took the test.

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What property of Granite makes it useful for making roads

Flura [38]

Answer:igneous rock

Explanation:

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3 years ago

100 PTS IM DESPERATE NEED BY TOMMOROW

faust18 [17]

Answer:

rest will do later mom is calling me plz understand promise will do it

Explanation:

Elements and compounds are similar in that they are both made of atoms and in some cases molecules.
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4 0

3 years ago

Nitrogen dioxide and water react to form nitric acid and nitrogen monoxide, like this:

dybincka [34]

Answer:

0.29

Explanation:

Step 1: Write the balanced equation at equilibrium

3 NO₂(g) + H₂O(l) ⇄ 2 HNO₃(aq) + NO(g)

Step 2: Calculate the molar concentration of the substances

We will not calculate the molarity of H₂O because pure liquids are not included in the equilibrium constant. We will use the following expression.

Molarity = mass of solute / molar mass of solute × liters of solution

Since the volume of the vessel is missing, we will assume it is 1 L to see the procedure.

[NO₂] = 22.5 / 46.01 g/mol × 1 L = 0.489 M

[HNO₃] = 15.5 g / 63.01 g/mol × 1 L = 0.246 M

[NO] = 16.6 g / 30.01 g/mol × 1 L = 0.553 M

Step 3: Calculate the value of the equilibrium constant Kc for this reaction

Kc = [HNO₃]² × [NO] / [NO₂]³

Kc = 0.246² × 0.553 / 0.489³

Kc = 0.29

7 0

3 years ago

Chloroacetic acid, ClCH2COOH, has a pKa of 2.87. What are [H3O+], pH, [ClCH2COO−], and [ClCH2COOH] in 1.55 M ClCH2COOH?

Mademuasel [1]

Answer:

See explanation below

Explanation:

first to all, this is an acid base reaction where the chloroacetic acid is being dissociated in water. Therefore, is an equilibrium reaction.

ClCH₂COOH has a pKa of 2.87 so, the Ka would be:

pKa = -logKa ---> Ka = antlog(-pka)

Ka = antlog(-2.87)

Ka = 1.35x10⁻³

Now that we know the Ka, we need to write the chemical reaction and then, an ICE chart:

ClCH₂COOH + H₂O <----------> ClCH₂COO⁻ + H₃O⁺ Ka = 1.35x10⁻³

i) 1.55 0 0

c) -x +x +x

e) 1.55-x x x

Writting now the equilibrium reaction:

Ka = [H₃O⁺] [ClCH₂COO⁻] / [ClCH₂COOH]

Replacing the values of the chart:

1.35x10⁻³ = x² / 1.55-x

1.35x10⁻³(1.55-x) = x²

2.0925x10⁻³ - 1.35x10⁻³x = x²

x² + 1.35x10⁻³x - 2.0925x10⁻³ = 0 --> a = 1; b = 1.35x10⁻³x; c = 2.0925x10⁻³

From here we use the general equation for solve x in a quadratic equation which is:

x = -b±√(b² - 4ac) / 2a

Replacing the values we have:

x = -1.35x10⁻³ ±√(1.35x10⁻³)² - 4*1*(-2.0925x10⁻³) / 2

x = -1.35x10⁻³ ±√(8.37x10⁻³) / 2

x = -1.35x10⁻³ ± 0.091 / 2

x1 = -1.35x10⁻³ + 0.091 / 2 = 0.045 M

x2 = -1.35x10⁻³ - 0.091 / 2 = -0.046 M

In this case, we will take the positive value of x, in this case, x1.

With this value, the equilibrium concentrations are the following:

[H₃O⁺] = [ClCH₂COO⁻] = 0.045 M

[ClCH₂COOH] = 1.55 - 0.045 = 1.505 M

Finally the pH:

pH = -log[H₃O⁺]

pH = -log(0.045)

pH = 1.35

4 0

3 years ago

Benzyl ethyl ether reacts with concentrated aqueous HI to form two initial organic products (A and B). Further reaction of produ

Colt1911 [192]

Answer:

See answer for details

Explanation:

In this case, we have the following substract:

Ph-CH2 - O - CH2CH3

That's the benzyl ethyl ether.

When this compound reacts with a concentrated Solution of HI, as we have an acid medium, we will have an SN1 reaction, where the Hydrogen will attach to the oxygen and the iodine will go to the most stable carbon, in this case, the carbon next to the ring is the most stable (because of the double bond of the ring, charges can be stabilized better this way), so product A will be the benzyl with the iodine and product B, will be the alcohol:

A: Ph - CH2 - I

B: CH3CH2OH

When B reacts again with HI, it's promoting another SN1 reaction, where the OH substract the H from the HI, the OH2+ will go out the molecule, leaving a secondary carbocation (CH2+) and then, the Iodine (I-) can go there via SN1 and the final product would be:

C: CH3CH2I

See picture for mechanism:

5 0

3 years ago