The Lewis structure/diagram for CH2O (aka Formaldehyde) can be written in either of the following ways shown in the picture.
The dots represent electrons in the valence shell of the atom (the outermost shell). The green dots are electrons that belong to the Oxygen atom, the blue belong to the Carbon atom, and the pink belong to the Hydrogen atoms.
Covalent bonds are bonds between atoms where atoms share electrons with each other. Atoms bond because they obey the octet rule ( the rule states that most atoms of main-group elements tend to want 8 electrons in their valence shells).
Oxygen has 6 valence electrons, Carbon has 4, and Hydrogen has 1. H does not follow the octet rule, but C and O do, so the atoms are arranged in this way so that the O and C atoms have a full octet of electrons in their valence.
The correct answers about rusting, air pollution and products of water with rock are:
Option A. oxidation
Option D. Pollutants mix with air and water to make acid rain.
Option B. clay minerals and calcium carbonate
<h3>What is rusting?</h3>
Rusting is the process by which a metal especially reacts with oxygen in the atmosphere and water vapor to form a hydrated oxide of the metal known as hydrated iron (iii) oxide. This is known as rust.
The process is an oxidation process; option A.
<h3>How does air pollution impact chemical weathering?</h3>
Air pollution is the presence of substances in air known as pollutants which makes the air impure.
Air pollution impact chemical weathering as the pollutants mix with air and water to make acid rain which weathers rocks; option D.
<h3>What products are produced when water reacts with sodium in rocks?</h3>
The reaction of water with sodium in rocks result in the formation of clay minerals and calcium carbonate also as limestone, marble or chalk; option B.
In conclusion, the presence of pollutants in air results in acid rain and hence rock weathering.
Learn more rock weathering at: brainly.com/question/2341950
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<span>Ores are naturally occurring rocks that contain metal or metal compounds in sufficient amounts to make it worthwhile extracting them. For example, iron ore is used to make iron and steel.</span>
Answer:
We will expect 4 moles of MgO to be formed (option b).
Explanation:
Step 1: The balanced equation
2Mg + O2 → 2MgO
Step 2: Data given
Number of moles of Magnesium = 4 moles
Oxygen = in excess → this means Magnesium is the limiting reactant
Magnesium will completely be consumed ( 4 moles). There will remain 0 moles.
For 2 moles of magnesium consumed, we need 1 mole of oxygen to produce 2 moles of MgO.
For 4 moles of magnesium, we need 4/2 = 2 moles of oxygen.
For 4 moles of magnesium, we will produce 4/1 = 4 moles of MgO
We will expect 4 moles of MgO to be formed (option b).
Answer:
a) a = 3485 M⁻¹cm⁻¹
b) C = 0,000127 M
Explanation:
Lambert-Beer law says that there is a linear relationship between absorbance and concentration of a chemical substance. The formula is:
A = a×b×C
Where A is absorbance, a is molar absorptivity, b is path length and C is concentration.
a) In the problem Concentration is 0.0000792 M, b is 1,000cm and Absorbance is absorbance of sample-absorbance of blank: 0,341-0,065 = 0,276
Replacing:
0,276 = a×1,000cm×0,0000792M
<em>a = 3485 M⁻¹cm⁻¹</em>
b) As the experiment consist in the same compound in the same solvent, the molar absorptivity will be the same, a = 3485 M⁻¹cm⁻¹, path length will be 1,000cm and absorbance: 0,508-0,065 = 0,443
Replacing:
0,443 = 3485 M⁻¹cm⁻¹×1,000cm×C
<em>C = 0,000127 M </em>
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I hope it helps!
