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3 years ago

True or false. Microwaves heat food evenly.

Chemistry

2 answers:

maria [59]3 years ago

4 0

False. It depends on how much time you put into it like 2 minutes or 30 seconds

Art [367]3 years ago

4 0

Answer:

False

Explanation:

When you continuously feed waves into space, there are going to be some cold spots, or "dead spots."

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8,403 kg =----------g

umka2103 [35]

Answer:

8,403,000 grams

Explanation:

1 kg = 1000 grams, so just multiply by a factor of 1000

6 0

4 years ago

Read 2 more answers

A gas mixture of Ne and Ar has a total pressure of 4.00 atm and contains 16.0 mol of gas. If the partial pressure of Ne is 2.75

Stolb23 [73]

Answer:

5 moles of Argon is present in the mixture.

Explanation:

Total pressure of the gaseous mixture = 4 atm

Total number of moles = 16

Partial pressure of Ne = 2.75 atm

By Dalton's law of partial pressure, the total pressure of gaseous mixture is the sum of partial pressures of individual gases which are non-reactive.

Hence:

$P_{total}=P_{Ar}+P_{Ne}\\4=P_{Ar}+2.75\\P_{Ar}=1.25\ atm$

Also :

Partial pressure = mole fraction*total pressure

$P_{Ar}=X_{Ar}P_{total}$

$X_{Ar}=\frac{1.25}{4}=0.3125$

$\frac{n_{Ar}}{n_{total}}=0.3125\\n_{Ar}=5$

∴Number of moles of Argon = 5

4 0

4 years ago

Based on the information given, classify each of the pure substances as elements or compounds, or indicate that no such classifi

Olenka [21]

Answer:

Analysis with an elaborate instrument indicates that:

Substance A contains two elements.

Compound

Substance B and substance C react to give a new substance D.

Insufficient information

Substance E decomposes upon heating to give substance F and substance G.

Compound

Heating substance H to 1000 °C causes no change.

Insufficient information

Substance I cannot be broken down into simpler substances by chemical means.

Element

Substance J cannot be broken down into simpler substances by physical means

Insufficient information

Explanation:

Important background:

Pure substances are elements or compounds.

Elements are formed by only one kind of atoms. They cannot be broken down into another substance by chemical or physical means. There are only 118 known elements; they are all listed in the periodic table.

Compounds have fixed chemical composition and are formed by two or more kind of atoms, chemically bonded. They can be broken down into different pure substances, either elements or other substances, only by chemical changes.

With tha information let's see every statement about the pure substances that should be classified as elements or compounds.

Substance A contains two elements: compound

Since, the pure substance contains two elements, it is not just and element by a compound. This is because a compound is a pure substance composed of two or more elements.

Substance B and substance C react to give a new substance D.: Insufficient information

Either two elements, one element and one compound, or two compounds may react to give a new substance, so you cannot assure what kind of pure substance B and C are.

For instance:

- two elements like hydrogen and oxygen reacto to give water (a compound)

- a compound like CH₂=CH₂ react with an element like Cl₂ to give CH₂Cl-CH₂Cl

Substance E decomposes upon heating to give substance F and substance G. : Compound

An element cannot be decomposed into two different substances, since the elements are composed by just one kind of atoms.

So, if the substance E decomposes into two different substances, F and G, E necessarily has to be a compound.

Heating substance H to 1000 ∘C causes no change. Insufficient information

The mere fact that a substance has not changed by heating at such extreme temperature cannot assure whether the substance is a compound or an element.

Some compounds are stable at very high temperatures. For instace, magnesium oxide, MgO, has a melting point of 2852°C, meaning that it will remain a a solid substance way beyond 1,000°C

Substance I cannot be broken down into simpler substances by chemical means. Element

Since an element is formed by one single kind of atoms, it cannot be broken down into simpler substances by chemical means; but a compose does, because it is formed by two or more different elements chemically bonded.

Substance J cannot be broken down into simpler substances by physical means: Insufficient information

The distintion between compounds and elements is based on chemical changes; the fact that physical changes do not change the substance does not tell anything about the fact that the substance is composed by one kind of elements or several elements chemical boonded.

Hence, physical means do not provide sufficient information to conclude about whether a substance is an element or a compound.

4 0

3 years ago

Calculate the pOH of an aqueous solution of .0.073 M LiOH

Novosadov [1.4K]

Considering the definition of pOH and strong base, the pOH of the aqueous solution is 1.14

The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution and indicates the concentration of ion hydroxide (OH-).

pOH is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:

pOH= - log [OH⁻]

On the other hand, a strong base is that base that in an aqueous solution completely dissociates between the cation and OH-.

LiOH is a strong base, so the concentration of the hydroxide will be equal to the concentration of OH-. This is:

[LiOH]= [OH-]= 0.073 M

Replacing in the definition of pOH:

pOH= -log (0.073 M)

pOH= 1.14

In summary, the pOH of the aqueous solution is 1.14

Learn more:

7 0

3 years ago

What happens to the shape of a liquid when you pour it into a container?

LenKa [72]

It shifts and the temperature changes I think hope this helps

8 0

4 years ago