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3 years ago

7 g of table salt is added to water in a dish. The dish is then heated until all the water evaporates. This is an example of a

Chemistry

1 answer:

butalik [34]3 years ago

8 0

Answer:

Physical change

Explanation:

A physical change is one in which no new substance is formed and can be reversed using physical methods.

When we mix the salt and water, we have merely carried out a physical change. No new substance was formed. To recover the salt, we simply heat the solution to dryness.

Hence, this is an example of a physical change.

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What is non stoichiometric reaction ?

yanalaym [24]

Nonstoichiometric compounds are chemical compounds deviated from stoichiometry, namely, their elemental composition cannot be represented by a ratio of well-defined natural numbers, and therefore they violate the law of definite proportions.

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4 years ago

Which of the following describes an element? Choose all that apply.

Svetradugi [14.3K]

Answer: Element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron

Explanation:a b d

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3 years ago

When does heat naturally move from cooler objects to warmer objects

Blizzard [7]

<span>Conduction occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature. Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object. </span>

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4 years ago

If I have 1.9 moles of gas held at a pressure of 5 atm and in a container with a volume of 100 liters, what is the temperature o

Ivahew [28]

Answer:

T = 3206.89 K

Explanation:

Given that,

Number of moles, n = 1.9 moles

Pressure, P = 5 atm

Volume, V = 100 L

We need to find the temperature of the gas. Let the temperature is T. We know that,

PV = nRT

Where

R is gas constant, R = 0.08206 L-atm/mol-K

Put all the values,

$T=\dfrac{PV}{nR}\\\\T=\dfrac{5\times 100}{1.9\times 0.08206 }\\\\T=3206.89\ K$

So, the temperature of the gas is 3206.89 K.

7 0

3 years ago

In a undisturbed layer, how do we know which layer was deposited first ?

OLEGan [10]

Answer:

It's the bottom layer.

Explanation:

Scientists use the Law of Superposition to determine the relative age of a layer of sedimentary rock:

The oldest rock layer is at the bottom of an undisturbed bed.

Thus, Layer A in the figure below was deposited first.

8 0

3 years ago