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3 years ago

What does a chemist do

1 answer:

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A chemist (from Greek chēm (ía) alchemy; replacing chemist from Medieval Latin alchimista[1]) is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, reaction rates, and other chemical properties. The word 'chemist' is also used to address Pharmacists in Commonwealth English.

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A piece of neutral litmus paper turned red in some grapefruit juice.  What does this show about the grapefruit juice

Elodia [21]

Answer:

grapefruit juice is an acid

Explanation:

A piece of neutral litmus paper turned red in some grapefruit juice. What does this show about the grapefruit juice

with litmus paper remember:

E R

S E

ACID

BLUE

acids turn litmus red, bases turn it blue

all citrus fruits :llemons, lime, grapefruit, oranges, etc are called

CITRUS FRUITS because they contain citric acid

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2 years ago

An exothermic reaction occurs spontaneously ,why?

Delvig [45]

Answer:

See below

Step-by-step explanation:

An exothermic reaction tends to occur spontaneously because the products are more stable than the reactants.

Nature tries to get to the lowest energy state.

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2 years ago

HURRY PLEASE

katrin2010 [14]

Answers:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

Explanations:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

The table shows that the melting point of gallium is 30°C and its boiling point is 2204°C.

Melting point is the temperature at which the substace changes its state from solid to liquid. During that change, the temperature of the substance does not change, because the heat supplied is used to accomplish the phase change. So, the temperature is constant and that means that portion of the diagram is flat.

The same is valid during boiling: the temperature remains constant while the substance is passing from liquid to gas at the boiling point.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Between the melting (-183°C) and boiling (-162°C) points of methane, its temperature will increase more or less linearly, which is represented with a diagonal (slant) line between those points. During this interval the heat is used to increase the temperature and no phase of change happens.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

The table shows that the boiling point of gold is 2,856°C.

In a temperature-vs.-time diagram the temperature is represented on the vertical axis (y-value) and the time is represented on the horizontal axis.

Since, the temperature of the substance does not change during boiling, the line during the time that this change of phase is happening is flat. And since this temperatue is higher than the melting temperature, this is the top horizontal line in the diagram.

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

The table shows that the melting point of nitrogen is -210°C, that means that the temperature will remain constant at -210°C while the substance is absorbing heat to pass from solid to liquid.

In conclusion, you must remember that all the phase changes, melting (from solid to liquid), freezing (from liquid to solid), boilng (from liquid to gas), and condensing (from gas to liquid) happens at constant temperature, and so the temperature - vs. - time diagrams show flat lines (constant y-values) during those intervals of time.

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2 years ago

Read 2 more answers

How can you use chemistry to enhance ground transportation vehicles and reduce pollution?

Svetradugi [14.3K]

Answer:

Ride a bike or walk. If you are only going a short distance, consider riding a bike or walking instead of driving. ...

Take public transit. ...

Carpool. ...

Avoid idling. ...

Use alternative fuels.

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