Answer:
B. 126
Explanation:
the scale is 1 to 42 so the scale would be:
3 cm:x cm
3 * 42 = 126 cm
Surface tension is the result of water molecules pulling inward with a strong attractive force.
The attractive force brings the molecules on the surface of the water close together.
The attractive force causes the surface of the water to be drawn toward the water molecules beneath the surface. <span>
Since there are no water molecules above the surface, there are uneven forces. This causes surface tension, allowing the coin to float on the water’s surface.</span>
Answer : Methanal also known as Formaldehyde 
is a chemical Aldehyde which contain ( -CHO) group.
Explanation :
In organic chemistry, a carbonyl group is a functional group which contain a carbon atom double-bonded to an oxygen atom i.e, ( C=O).
If carbonyl group is present in a compound then it can be a carboxylic (RCOOH), aldehyde (RCHO), ketone (RCOR'), ester ((RCOOR') or amide (RCONR'R") group.
Here are some functional groups naming according to the<em> IUPAC</em> rules and image also attached,
Carboxylic acid → (RCOOH) → ( name end in 'OIC ACID' )
Aldehyde → (RCOH) → ( name end in 'AL' )
Ketone → (RCOR') → ( name end in 'ONE' )
Ester → (RCOOR') → ( name end in 'ATE' )
Amide → (RCONR'R") → ( name end in 'AMIDE' )
In an aldehyde, atleast one hydrogen atom must be attached to the carbonyl carbon. For an aldehyde, remove ( -e) from alkane name and add ( -al) at the end of the compound.
Methanal is the IUPAC name for Formaldehyde.
The required formula of hydrate is MgSO₃.6H₂O.
<h3>How do we calculate the formula of hydrate?</h3>
The number of moles of water per mole of anhydrous solid (x) will be computed by dividing the number of moles of water by the number of moles of anhydrous solid (x) to find the hydrate's formula.
Moles will be calculated as:
n = W/M, where
- W = given mass
- M = molar mass
Moles of MgSO₃ = 0.737g / 104.3g/mol = 0.007mol
Moles of H₂O = 0.763g / 18g/mol = 0.04 mol
Number of H₂O molecule = 0.04/0.007 = 5.7 = 6
So formula of hydrate is MgSO₃.6H₂O.
Hence required formula of hydrate compound is MgSO₃.6H₂O.
To know more about hydrate compound, visit the below link:
brainly.com/question/22411417
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