It is too early for students to have career preferences while still in school
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Answer: There are
atoms of hydrogen are present in 40g of urea,
.
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.

According to the mole concept, 1 mole of every substance contains
atoms.
So, the number of atoms present in 0.67 moles are as follows.

In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.

Thus, we can conclude that there are
atoms of hydrogen are present in 40g of urea,
.
A. Mutualism
Mutualism: Both organism benefit
Commensalism: One organism benefits. One organism is unaffected
Parasitism: One organism benefits. One organism is harmed
Answer : The standard enthalpy of formation of methanol is, -238.7 kJ/mole
Explanation :
Standard formation of reaction : It is a chemical reaction that forms one mole of a substance from its constituent elements in their standard states.
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of
will be,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

Now we will reverse the reaction 3, multiply reaction 2 by 2 then adding all the equations, we get :
(1)

(2)

(3)

The expression for enthalpy of formation of
will be,



Therefore, the standard enthalpy of formation of methanol is, -238.7 kJ/mole
I believe the compound KOI is meant to be potassium iodate, which is KIO₃. This compound will also be the one with the highest melting point.
This is due to the fact that potassium ion will form ionic bonds with whatever atom or molecule it binds to. Ionic bonds involve the complete transfer of electrons, making them very strong and hard to break, meaning the compound will have the highest melting point.