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2 years ago

11. Which of the following is a characteristic of all chemical changes? *

Chemistry

1 answer:

Shtirlitz [24]2 years ago

4 0

Answer:

Explanation:

A new Material is formed.

Basically, Chemical changes differ from Physical changes because in chemical changes, Substances have the ability to become a different substance.

Example:

Water to ice is a physical change because it is still water despite being a solid from liquid.

A Magnesium strip placed in CuSO4 solution made the Mg strip turn into a new substance which is MgSO4. this is a Chemical change because Mg has now become a different substance called MgSO4.

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What type of energy is carried by electrical charges as they move in a circuit?

Usimov [2.4K]

B. Electrical energy

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2 years ago

Compound Y has a distribution coefficient of 4.0 when extracted from water with chloroform, with Y being more soluble in chlorof

Aleks04 [339]

Answer:

There are needed 3 extractions to extract at least 95%

Explanation:

The distribution coefficient of a compound is defined as the ratio in concentration of the compound in the organic solvent and the concentration in the aqueous solution:

K = Concentration organic solvent / Concentration in water

Assuming as initial amount of the organic solvent: 100% and X as the amount of Y that is extracted

First extraction:

4 = X / 10mL / (100-X) / 50mL

4 = 50X / 1000-X

4000 - 4X = 50X

4000 = 54X

X = 74.1%

In the first extraction, 74.1% of Y is extracted

And will remain: 100 - 74.1 = 25.9%

Second extraction:

4 = X / 10mL / (25.9-X) / 50mL

4 = 50X / 259-X

1036 - 4X = 50X

1036 = 54X

X = 19.2%

In the second extraction, 19.2% of Y is extracted

And will remain: 25.9 - 19.2 = 6.7%

Third extraction

4 = X / 10mL / (6.7-X) / 50mL

4 = 50X / 67-X

268 - 4X = 50X

268 = 54X

X = 5.0%

In the first extraction, 5.0% of Y is extracted

And are extracted:

74.1% + 19.2% + 5.0% = 98.3%

That means there are needed 3 extractions to extract at least 95%

4 0

2 years ago

Summarize the process a scientist goes through to come up with a satisfactory solution.

maria [59]

Guess and check, test, trial and error, completion.

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3 years ago

How many moles are in 35.6 g of H2O

klasskru [66]

Answer:

Given

mass of H2O (m) =35.6g

molarmass (mr) = H2O ), 1x2+16=18g/mol

moles of H2O (n) =?

sln

n=m/mr

n=35.6g/18g/mol

n=1.978moles

the moles of H2O are 1.978moles

3 0

2 years ago

What pressure is required to compress 196.0 liters of air at 1.83 atmosphere into a cylinder whose volume is 26.0 liters

drek231 [11]

Answer:

P₂ = 13.79 atm

Explanation:

Given data:

Initial volume = 196.0 L

Initial pressure = 1.83 atm

Final volume = 26.0 L

Final pressure = ?

Solution:

The given problem will be solved through the Boyle's law,

"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"

Mathematical expression:

P₁V₁ = P₂V₂

P₁ = Initial pressure

V₁ = initial volume

P₂ = final pressure

V₂ = final volume

Now we will put the values in formula,

P₁V₁ = P₂V₂

1.83 atm × 196.0 L = P₂× 26.0 L

P₂ = 358.68 atm. L / 26.0 L

P₂ = 13.79 atm

5 0

2 years ago