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Greeley [361]
3 years ago
14

Early Earth was largely anoxic with very little oxygen present in the atmosphere. However, approximately 2 billion years ago, a

rise in atmospheric oxygen concentration was recorded in the geological record. This event, known as the great oxygenation event (GOE), was caused by small microorganisms (cyanobacteria) that likely carried out the process of ____________________ .
Chemistry
1 answer:
blagie [28]3 years ago
8 0

Answer:

Photosynthesis

Explanation:

Cyanobacteria were the first prokaryotic organisms capable of oxygen-evolving complex. Photosynthesis needs an electron source, in this case water (H2O). By photo-oxidation of the water, oxygen (O2) is released (and hydrogen taken).

This led to the accumulation of oxygen in the atmosphere where it got to similar concentrations as in these days.  

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What is the main reason that attitudes are more often revealed in spoken rather than written language?
musickatia [10]
I believe the answer is D.
6 0
4 years ago
0.352 g sample of a diprotic acid is dissolved in water and titrated with 0.150 M NaOH.0.150 M NaOH. What is the molar mass of t
Aliun [14]
<h3>Answer:</h3>

128.94 g/mol

<h3>Explanation:</h3>

Given;

Mass of diprotic acid, H₂X =0.352 g

Molarity of NaOH = 0.150 M

Volume of the NaOH = 36.4 mL

We are required to calculate the molar mass of the acid.

Note: A diprotic acid is an acid that contains 2 replaceable hydrogen atoms

<h3>Step 1: Write the balanced equation fro the reaction;</h3>

The balanced equation for the reaction between the diprotic acid and NaOH will be;

H₂X(aq) + 2NaOH(aq) → Na₂X(aq) + 2H₂O(l)

<h3>Step 2: Determine the number of moles of NaOH used </h3>

Given the molarity and volume of NaOH we can calculate the number of moles;

Moles of NaOH = Molarity × Volume

                          = 0.150 M × 0.0364 L

                         = 0.00546 moles

<h3>Step 3: Use the mole ratio to determine moles of the acid </h3>

From the equation;

1 mole of the acid reacts with 2 moles of NaOH

Therefore; H₂x : NaOH = 1 : 2

Moles of H₂x = 0.00546 moles ÷ 2

                      = 0.00273 moles

<h3>Step 4: Determine the molar mass of the acid.</h3>

Molar mass is the mass equivalent to 1 mole of a compound or element

From our calculations;

0.00273 moles = 0.352 g of the acid;

Therefore, mass in 1 mole ;

= 0.352 g ÷ 0.00273 moles

= 128.94 g/mol

Thus, the molar mass of the diprotic, H₂X is 128.94 g/mol

7 0
3 years ago
What type of bonding exists between the carbon atoms to create diamond ?
Step2247 [10]

Answer:

Covalent bonds.

Explanation:

Diamond is organized in a giant lattice structure with strong covalent bonds between carbon atoms. Each carbon atom forms 4 bonds. Explanation: Each carbon atom has four electrons in its outer shell, all of which form covalent bonds that are strong and hard to break.

5 0
3 years ago
The equation shows one mole of ethanol fuel being burned in oxygen. Convert the energy released into its equivalent mass. C2H5OH
lana [24]

Answer:

47.9 g of ethanol

Explanation:

Combustion is a chemical reaction in which a substance reacts with oxygen to produce heat and light. Combustion reactions have been very useful as a source of energy. Ethanol is now burnt for energy purposes as a fuel. Ethanol has even been proposed as a possible alternative to fossil fuels.

Since 1 mole of ethanol when combusted releases 1367 kJ/mol of energy

x moles of ethanol releases 1418 kJ/mol.

x= 1 × 1418 kJ/mol/ 1367 kJ/mol

x= 1.04 moles of ethanol.

Mass of ethanol = number of moles × molar mass

Molar mass of ethanol = 46.07 g/mol

Mass of ethanol = 1.04 moles × 46.07 g/mol

Mass of ethanol= 47.9 g of ethanol

7 0
3 years ago
Describe how transverse waves can be produced on a rope
goblinko [34]
Move your rope up and down and that will create transverse waves.
Was this helpful?
4 0
3 years ago
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