All categories

2 years ago

In what era did reptiles become increasingly dominant?

Chemistry

2 answers:

emmainna [20.7K]2 years ago

6 0

Correct answer: B. Paleozoic. I took the test and it was right.

Leni [432]2 years ago

5 0

Palezoic I took the test!!

You might be interested in

How many chromium (II) ions would bond with 2 phosphate ions?

zvonat [6]

Answer:

ummmm I don't know of sorry

3 0

1 year ago

Which of the following IS a part of the Kinetic Molecular Theory (KMT)?

Arisa [49]

The statement that is a part of Kinetic Molecular Theory (KMT) is Molecules in a gas move rapidly. That is option B.

<h3>What is Kinetic Molecular Theory (KMT)?</h3>

Kinetic Molecular Theory (KMT) is defined as the theory that describes the physical behaviour of gases.

The Kinetic Molecular Theory (KMT) include the following:

Ideal gas molecules are constantly moving;

They have negligible volume;

They have negligible intermolecular forces;

They undergo perfectly elastic collisions; and

They have an average kinetic energy proportional to the ideal gas's absolute temperature.

Therefore, the statement that is a part of Kinetic Molecular Theory (KMT) is Molecules in a gas move rapidly.

Learn more about gas here:

brainly.com/question/25649765

#SPJ1

5 0

1 year ago

In an exothermic reaction, the water will _______ in a calorimeter. A. release heat B. drop in temperature C. drop in volume D.

elena-14-01-66 [18.8K]

the correct answer is D, absorb heat

7 0

2 years ago

Read 2 more answers

Calculate the molar solubility of PbBr2 (Ksp = 4.67x10-6) in 0.10M NaBr solution.

Softa [21]

Explanation:

$PbBr_{2}$ will dissociate into ions as follows.

$PbBr_{2}(s) \rightleftharpoons Pb^{2+}(aq) + 2Br^{-}(aq)$

Hence, $K_{sp}$ for this reaction will be as follows.

$K_{sp} = [Pb^{2+}][Br^{-}]^{2}$

We take x as the molar solubility of $PbBr_{2}$ when we dissolve x moles of solution per liter.

Hence, ionic molarities in the saturated solution will be as follows.

$[Pb^{2+}]$ = $[Pb^{2+}]_{o}$ + x

$[Br^{-}]^{2}$ = $[Br^{-}]_{o}$ + 2x

So, equilibrium solubility expression will be as follows.

$K_{sp}$ = $([Pb^{2+}]_{o} + x)([Br^{-}]_{o} + 2x)^{2}$

Each sodium bromide molecule is giving one bromide ion to the solution. Therefore, one solution contains $[Br^{-}]_{o}$ = 0.10 and there will be no lead ions. So, $[Pb^{2+}]_{o}$ = 0

So, $[Br^{-}]_{o} + 2x$ will approximately equals to $[Br^{-}]_{o}$ .

Hence, $K_{sp} = x[Br^{-}]^{2}_{o}$

$4.67 \times 10^{-6} = x \times (0.10)^{2}$

x = $4.67 \times 10^{-4}$ M

Thus, we can conclude that molar solubility of $PbBr_{2}$ is $4.67 \times 10^{-4}$ M.

5 0

2 years ago

Read 2 more answers

What is the theoretical yield of aspirin ( C 9 H 8 O 4 ), which has a molar mass of 180.15 g/mol, possible when reacting 3.03 g

pantera1 [17]

Answer:

The theoretical yield of aspirin is 3.95 grams

Explanation:

Step 1: Data given

Mass of salicylic acid = 3.03 grams

Volume of acetic anhydride = 3.61 mL

Density of acetic anhydride = 1.08 g/cm³

Step 2: The balanced equation

C4H6O3+C7H6O3→C9H8O4+C2H4O2

Step 3: Calculate moles salicylic acid

Moles salicylic acid = mass salicylic acid / molar mass salicylic acid

Moles salicylic acid = 3.03 grams /138.121 g/mol

Moles salicylic acid = 0.0219 moles

Step 4: Calculate mass acetic anhydride

Mass acetic anhydride = volume * density

Mass acetic anhydride = 3.61 mL * 1.08 g/mL

Mass acetic anhydride = 3.90 grams

Step 5: Calculate moles acetic anhydride

Moles acetic anhydride = 3.90 grams / 102.09 g/mol

Moles acetic anhydride = 0.0382 moles

Step 6: Calculate limiting reactant

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

Salicylic acid is the limiting reactant. It will completely be consumed. (0.0219 moles). Acetic anhydride is in excess. There will react 0.0219 moles. There remain 0.0382 - 0.0219 =0.0163 moles

Step 7: Calculate moles aspirin

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

For 0.0219 moles salicylic acid we'll have 0.0219 moles aspirin

Step 8: Calculate theoretical yield of aspirin

Mass of aspirin = moles aspirin *molar mass aspirin

Mass of aspirin = 0.0219 moles *180.15 g/mol

Mass of aspirin = 3.95 grams

The theoretical yield of aspirin is 3.95 grams

7 0

2 years ago