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morpeh [17]
3 years ago
5

A substance produced by some insects that was used to make records before world war II

Chemistry
1 answer:
ryzh [129]3 years ago
7 0
Are you doing that science crossword puzzle?
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Calculate the final Celsius temperature when 634 L at 21 °C is compressed to 307 L.
Illusion [34]

Answer:

- 130.64°C.

Explanation:

  • We can use the general law of ideal gas:<em> PV = nRT.</em>

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

  • If n and P are constant, and have two different values of V and T:

<em>V₁T₂ = V₂T₁</em>

<em></em>

V₁ = 634.0 L, T₁ = 21.0°C + 273 = 294.0 K.

V₂ = 307.0 L, T₂ = ??? K.

<em>∴ T₂ = V₂T₁/V₁ </em>= (307.0 L)(294.0 K)/(634.0 L) = <em>142.36 K.</em>

<em>∴ T₂(°C) = 142.36 K - 273 = - 130.64°C.</em>

5 0
3 years ago
Use the following equation to answer the questions below.
kaheart [24]

Answer:

1-Double replacement

Explanation:

3 0
2 years ago
What identifies a flaw in J. J. Thomson’s model of the atom?
katrin [286]

Answer:

The plum-pudding model did not identify a central nucleus as the source of a positive charge.

Explanation:

Sir Joseph John Thomson, most popularly known as J J Thomson. He was a famous scientist who was awarded the Noble prize for Physics for his discovery of the subatomic particle, electron.

He placed his famous model of an atom which is known as plum pudding model. He proposed that the atoms are described as the negative particles that is floating within a soup of the diffuse positive charge.

But the main defect of his proposal was that it did not recognized the presence of a central nucleus as a positive charged source.

3 0
2 years ago
Lewis acids and bases are most closely associated with which process?
Evgen [1.6K]
<span>Lewis acids and bases are most closely associated with ELECTRON TRANSFER. A Lewis acid is defined as as a chemical specie that can accept an electron pair from a Lewis base to form a Lewis adduct while a Lewis base is defined as a specie which can donate an electron pair to a Lewis acid or an acceptor compound. Thus, Lewis base and acid has to do with electrons transfer.</span>
8 0
2 years ago
Read 2 more answers
It has been proposed that North America is moving west 2cm per year. How many kilometers would it move in 5,000 years?
vazorg [7]

The answer is .1 kilometers because 2 times 5,000 equals 10,000 cm.

hope this helps

7 0
3 years ago
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