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Viefleur [7K]
3 years ago
6

How many millions of years ago did the earliest marine reptiles evolve from land reptiles?

Chemistry
2 answers:
Nezavi [6.7K]3 years ago
6 0
Roughly 240 million years ago
nydimaria [60]3 years ago
3 0
About 240 million years ago
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What is the number of moles in 10.62 L of H2S gas at STP?
Lina20 [59]

Answer:

0.474 moles

Explanation:

divide 10.62 by 22.4.

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3 years ago
PLEASE HELP IM STUGGLING
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A 2.684-g sample of zinc oxide was reduced by hydrogen gas, resulting in 2. 156 g of pure zinc metal. Determine the empirical fo
Afina-wow [57]

The empirical formula of the initial zinc oxide is ZnO.

<h3>What is Empirical Formula?</h3>

The empirical formula of a compound represents the ratios of elements in a compound but not the actual numbers or arrangement of the atoms.

It is the lowest whole number ratio of the element in the compound.

<h3>How to find out the empirical formula?</h3>
  • Find out the given masses and molar masses of the elements

The molar mass of Zn = 65 gmol⁻¹

Given the mass of Zn = 2.156 g

The molar mass of Oxygen = 16 gmol⁻¹

The mass of Oxygen = Mass of a sample of zinc oxide - the mass of zinc metal

                                   = (2.684 - 2.156) g

                                   = 0.528 g

  • Find the number of moles of the elements in the compound

The number of moles is given by

n = \frac{m}{M}

where m = given mass and

M = Molar mass

Number of moles of Zinc = \frac{2.156}{65} = 0.033 moles

Number of moles of Oxygen =\frac{0.528}{16} = 0.033 moles

  • Find the simplest ratios of the elements in the compound. To find the ratios simply divide the number of moles by the lowest number of moles obtained.

Here, the number of moles is the same for both elements. Hence, the simplest ratio for Zn:O is 1:1.

Therefore, the empirical formula of zinc oxide is ZnO.

Learn more about the empirical formula:

brainly.com/question/1603500

#SPJ4

 

5 0
1 year ago
I need help ASAP! How many reactants and products are in each element according to the chemical equation above.
Len [333]

Answer:

O 4

C 1

1 sodium

3 H

Products

1 sodium

3 H

4 O

1 C

Explanation:

7 0
3 years ago
How many grams of NH3 can be produced from 2.35 mol of N2 and excess H2.
tatyana61 [14]
Since the molar ratio of N2 to Nh3 is 2:1, you can make twice as much NH3 by using N2. Therefore, you can make a maximum of 4.5 mol of NH3 assuming 100% yield.
6 0
4 years ago
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