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Tanzania [10]
3 years ago
9

How did oxygen come up to make 21% of the earth's present atmosphere?

Chemistry
1 answer:
MakcuM [25]3 years ago
4 0
Tiny organisms known as cyanobacteria, or blue-green algae.
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How much work does a gas do when it expands against a constant pressure of 0.600 atm from a volume of 50.00 mL to a volume of 44
miskamm [114]

Answer:

23.71J is the work that the gas do.

Explanation:

The work that a gas do under isobaric conditions follows the formula:

W = P*ΔV

<em>Where W is work in atmL, P is the pressure and ΔV is final volume -Initial volume In Liters</em>

Replacing with the values of the problem:

W = P*ΔV

W = 0.600atm*(0.44000L - 0.0500L)

W = 0.234atmL

In Joules (1atmL = 101.325J):

0.234atmL × (101.325J / 1 atmL) =

<h3>23.71J is the work that the gas do.</h3>

<em />

3 0
2 years ago
The molar heat of fusion of platinum (Pt) is 4.700 kcal/mol. How much heat must be added to 85.5 g of solid platinum at its melt
Andre45 [30]
The heat required to completely melt the given substance, platinum, we just have to convert first the given mass in mole and multiply the answer to its molar heat of fusion.. 
                              Hf  = mass x (1/molar mass) x molar heat of fusion
                            Hf = (85.5 g) x (1 mole/195.08 g) x 4.70 kcal/mol
                                   Hf = 2.06 kcal
4 0
3 years ago
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How is agriculture depended on industries​
gulaghasi [49]

Answer:

The interdependence of agriculture and industry helps the development of both the sectors. The most important aspect of this inter dependence is that the products of one serve as important inputs for the other. Growth of one sector, thus means ample supply of inputs for the other.

Explanation:

3 0
2 years ago
Why do different materials have similar properties
Deffense [45]

Answer:

The difference in the number of protons and neutrons in atoms account for many of the different properties of elements.

7 0
2 years ago
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Which solution has a molality of 0.25m nacl?
Solnce55 [7]

Molality can be expressed by moles of solute over kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl is equal to 0.25 moles of NaCl over 1 kg of water.

5 0
3 years ago
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