Answer:
Choice B. The solid with hydrogen bonding.
Assumption: the molecules in the four choices are of similar sizes.
Explanation:
Molecules in a molecular solid are held intact with intermolecular forces. To melt the solid, it is necessary to overcome these forces. The stronger the intermolecular forces, the more energy will be required to overcome these attractions and melt the solid. That corresponds to a high melting point.
For molecules of similar sizes,
- The strength of hydrogen bonding will be stronger than the strength of dipole-dipole attractions.
- The strength of dipole-dipole attractions (also known as permanent dipole) will be stronger than the strength of the induced dipole attractions (also known as London Dispersion Forces.)
That is:
Strength of Hydrogen bond > Strength of Dipole-dipole attractions > Strength of Induced dipole attractions.
Accordingly,
Melting point due to Hydrogen bond > Melting point due to Dipole-dipole attractions > Melting point due to Induced Dipole attractions.
- Induced dipole is possible between all molecules.
- Dipole-dipole force is possible only between polar molecules.
- Hydrogen bonds are possible only in molecules that contain
atoms that are bonded directly to atoms of 
, 
, or 
.
As a result, induced dipoles are the only force possible between molecules of the solid in choice C. Assume that the molecules are of similar sizes, such that the strengths of induced dipole are similar for these molecules.
Melting point in choice B > Melting point in choice D > Melting point in choice A and C.
Answer:
0.0933 moles/Litre
Explanation:
We assume that the number of moles of N- used is equal to the number of moles of Nitrogen containing compounds that are generated due to the fact that the nitrogen containing compound that are produced contain only one nitrogen in each atom. As such, finding the amount of nitrogen used up explains the amount of compound formed. This can be expressed as follows:
Energy cost = 
Given that:
Energy = 100 W for 60 minutes
100 W = 100 J/s
= 100 J/s × (60 × 60) seconds
= 3.6 × 10⁵ J
Let now convert 3.6 × 10⁵ J to eV; we have:
= ( 3.6 × 10⁵ × 6.242 × 10¹⁸ )eV
= 2.247 × 10²⁴ eV
So, number of N-atom used up to form compounds will now be:
= 2.247 × 10²⁴ eV × 
= 1.123 × 10²³ N-atom
To moles; we have:
= 
= 0.186 moles
However, we are expected to leave our answer in concentration (i.e in moles/L)
since we are given 2L
So; 0.186 moles ⇒ 
= 0.0933 moles/Litre
<h3>
Answer:</h3>
2(CH3)2N2H2 + 3N2O4 → 4N2 + 4H2O + 4CO2 + heat
<h3>
Explanation:</h3>
- Balancing chemical equations involves putting coefficients on reactants and products.
- This results in an equal number of atoms of each element on either side of the equation.
- Balancing chemical equations ensures that the law of conservation of mass is obeyed.
- According to the law of conservation of mass, the mass of the reactants should be equal to the mass of products which is done by balancing chemical equations.
- Putting the coefficients, 2, 3, 4, 4, 4 on the equation makes the equation balanced.
- Therefore, the balanced equation would be;
2(CH3)2N2H2 + 3N2O4 → 4N2 + 4H2O + 4CO2 + heat
Answer:
240 seconds
Explanation:
Data Given:
Distance Radio travel to earth = 7.19 ×10⁷ km
Speed of this radio signal = 3.00 ×10⁸ m/s
Solution:
First convert Km to m
1 km = 1000 m
7.19 ×10⁷ km = 7.19 ×10⁷ x 1000 = 7.19 × 10¹⁰m
Formula used to calculate time
Speed (S) = distance (d) / time (t)
rearrange above equation for time
time (t) = distance (d) / Speed (S) . . . . . . . . .(1)
Put values in equation 1
time (t) = 7.19 × 10¹⁰/ 3.00 ×10⁸ m/s
time (t) = 240 s
So 240 seconds it take for the signal to reach the earth
Answer:
TRUE: <span>Forces that act between two molecules are referred to as Intermolecular Forces.
Explanation:
Those forces which are present within the molecule among atoms are called as Intramolecular Forces, while, The forces which are present between two molecules are called as Intermolecular Forces. Intermolecular Forces are as follow,
1) Hydrogen Bond Interactions
2) Dipole-Dipole Interactions
3) London Dispersion Forces</span>
