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pogonyaev
3 years ago
10

In what eon did single-celled organisms appear?

Chemistry
1 answer:
fomenos3 years ago
4 0
Archean is what I think but there isn’t a clear answer
You might be interested in
Please help !!!
stiv31 [10]

Answer:

2KClO3 》》2KCl +3O2

C+ O2》》CO2

number of C moles

Required O2 moles (According to the mole ratio )

Relevant to the first equation, find the moles the KClO3, which is used to produce that amount of O2 moles

Now you can find the mass of KClO3

I mentioned the useful steps which can guide you to get the answer.

Explanation:

5 0
3 years ago
Which of the following remains would be most likely only be found as a compression fossil?
attashe74 [19]

Answer:

A Leaf

Explanation:

Compressions are the way that leaves are fossilized as the leaves are pressed firmly between hard layers of rock.

3 0
3 years ago
Read 2 more answers
Hazmat Poison gas is in what class?
Alik [6]

HAZMAT Class 6 Toxic and infectious substances.

8 0
2 years ago
Read 2 more answers
A 1.0857 gram pure sample of a compound containing only carbon, hydrogen, and oxygen was burned in excess oxygen gas. 2.190 g of
Goryan [66]

Answer:

  • C₂ H₄ O

Explanation:

<u>1) Mass of carbon (C) in 2.190 g of carbon dioxide (CO₂)</u>

  • atomic mass of C: 12.0107 g/mol
  • molar mass of CO₂: 44.01 g/mol
  • Set a proportion: 12.0107 g of C / 44.01 g of CO₂ = x / 2.190 g of CO₂
  • Solve for x:

         x = (12.0107 g of C / 44.01 g of CO₂ ) × 2.190 g of CO₂ = 0.59767 g of C

<u />

<u>2) Mass of hydrogen (H) in 0.930 g of water (H₂O)</u>

  • atomic mass of H: 1.00784 g/mol
  • molar mass of H₂O: 18.01528 g/mol
  • proportion: 2 × 1.00784 g of H / 18.01528 g of H₂O = x / 0.930 g of H₂O
  • Solve for x:

        x = ( 2 × 1.00784 g of H / 18.01528 g of H₂O) × 0.930 g of H₂O = 0.10406 g of H

<u>3) Mass of oxygen (O) in 1.0857 g of pure sample</u>

  • Mass of O = mass of pure sample - mass of C - mass of H
  • Mass of O = 1.0857 g - 0.59767 g - 0.10406 = 0.38397 g O

Round to four decimals: Mass of O = 0.3840 g

<u>4) Mole calculations</u>

Divide the mass in grams of each element by its atomic mass:

  • C: 0.59767 g / 12.0107 g/mol = 0.04976 mol
  • H: 0.10406 g / 1.00784 g/mol = 0.10325 mol
  • O: 0.3840 g / 15.999 g/mol = 0.02400 mol

<u>5) Divide every amount by the smallest value (to find the mole ratios)</u>

  • C: 0.04976 mol / 0.02400 mol = 2.07 ≈ 2
  • H: 0.10325 mol / 0.02400 mol = 4.3 ≈ 4
  • O: 0.02400 mol / 0.02400 mol = 1

Thus the mole ratio is 2 : 4 : 1, and the empirical formula is:

  • <u>C₂ H₄ O </u>← answer
3 0
3 years ago
For an endothermic reaction at equilibrium, the addition of a catalyst
Tatiana [17]

Answer:

causes no shift

Explanation:

6 0
3 years ago
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