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bezimeni [28]
2 years ago
10

How is an echo formed?

Chemistry
2 answers:
mojhsa [17]2 years ago
5 0

Answer: B

Explanation: echos cannot be made from light waves so C and D are out, and sound waves cannot travel into a surface. Also echos is sound waves bouncing that’s why in an empty room without furniture there’s an echo.

Finger [1]2 years ago
3 0

Answer:

It is none. Echo is formed when sound waves hit a hard surface.

Explanation:

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Which of the following would be a reasonable synthesis of CH3CH2CH2CH2OH?Group of answer choices
vampirchik [111]

Answer:

B. 1-Butene rightarrow (1) BH3: THF (2)H202, OH-

Explanation:

In the hydroboration of alkenes, an alkene is hydrated to form an alcohol with anti-Markovnikov orientation.

the reagent BH₃:THF is the way that borane is used in organic reactions. The BH₃ adds to the double bond of an alkene to form an alkyl borane. Peroxide hydrogen in basic medium oxidizes the alkyl borane to form an alcohol. Indeed, hydroboration-oxidation converts alkenes to alcohols by adding water through the double bond, with anti-Markovnikov orientation.

8 0
3 years ago
A chemist adds 0.60L of a 0.20/molL sodium thiosulfate Na2S2O3 solution to a reaction flask. Calculate the millimoles of sodium
Serggg [28]

Answer:

1.2×10² mmole of Na₂S₂O₃

Explanation:

From the question given above, the following data were obtained:

Volume = 0.6 L

Molarity = 0.2 mol/L

Mole of Na₂S₂O₃ =?

Molarity is simply defined as the mole of solute per unit litre of water. Mathematically, it is expressed as:

Molarity = mole /Volume

With the above formula, we can obtain the number of mole of Na₂S₂O₃ in the solution as illustrated below:

Volume = 0.6 L

Molarity = 0.2 mol/L

Mole of Na₂S₂O₃ =?

Molarity = mole /Volume

0.2 = Mole of Na₂S₂O₃ / 0.6

Cross multiply

Mole of Na₂S₂O₃ = 0.2 × 0.6

Mole of Na₂S₂O₃ = 0.12 mole

Finally, we shall convert 0.12 mole to millimole (mmol). This can be obtained as follow:

1 mole = 1000 mmol

Therefore,

0.12 mole = 0.12 mole × 1000 mmol / 1 mole

0.12 mole = 120 = 1.2×10² mmole

Thus, the chemist added 1.2×10² mmole of Na₂S₂O₃

7 0
3 years ago
explain what happens to the energy stored in an item after it stops working or is no longer functional. Explain in depth
gulaghasi [49]

Answer:

it gets rust and could not run properly

6 0
3 years ago
Are Si valence electrons shared? <br><br> Are C valence electrons shared?
MariettaO [177]

Answer:

4

Explanation:

Si has atomic number 14 so the electronic configuration 2,8,4

5 0
3 years ago
Water containing large amounts of Mg2+and Ca2+ions is said to be hard because it is hard to make soap lather in the water. True
mafiozo [28]

Answer:True

Explanation:

Water is said to be hard when it contains calcium ions or magnesium ions dissolved in it. These ions are able to react with soap in such a way that the soap is prevented from forming lather with the water. Hard water occurs when water passes over calcium or magnesium bearing minerals and dissolves some of it. Hardness due to the presence of calcium ions can easily be removed by boiling the water.

8 0
3 years ago
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