Answer:
1.811 g
Explanation:
The computation of the mass need to use to make the solution is shown below:
We know that molarity is

So,


= 0.031 moles
Now

where,
The Molecular weight of NaCl is 58.44 g/mole
And, the moles are 0.031 moles
So, the mass of NaCL is

= 1.811 g
We simply applied the above formulas
Answer:
atoms relative motion slow down and begin to vibrate in place
Answer : q = 6020 J, w = -6020 J, Δe = 0
Solution : Given,
Molar heat of fusion of ice = 6020 J/mole
Number of moles = 1 mole
Pressure = 1 atm
Molar heat of fusion : It is defined as the amount of energy required to melt 1 mole of a substance at its melting point. There is no temperature change.
The relation between heat and molar heat of fusion is,
(in terms of mass)
or,
(in terms of moles)
Now we have to calculate the value of q.

When temperature is constant then the system behaves isothermally and Δe is a temperature dependent variable.
So, the value of 
Now we have to calculate the value of w.
Formula used : 
where, q is heat required, w is work done and
is internal energy.
Now put all the given values in above formula, we get

w = -6020 J
Therefore, q = 6020 J, w = -6020 J, Δe = 0
Answer:
a) nitrogen
b) nitrogen =5
Oxygen = 6
Fluorine =7
Explanation:
Usually, if we have two or more elements in a compound, the central atom in the compound is the atom having the least value of electro negativity.
If we consider fluorine, oxygen and nitrogen; nitrogen is the least electronegative of the trio hence it should be the central atom of the triatomic molecule.
The number of valence electrons on the valence shell of each atom is shown below;
nitrogen =5
Oxygen = 6
Fluorine =7
The crust of the Earth is thickest beneath the continents.