Answer:
Y > X > Z
Explanation:
The intermoecular forces refer to forces that exist between molecules of a substance. They are the secondary bond forces that hold particles of a substance together in a particular state of matter.
The shorter the distance between molecules, the greater the magnitude of intermolecular force between the molecules.
The molecules of Y are at the shortest distance from each other hence they have the highest magnitude of intermolecular forces. Followed by X and lastly Z with the greatest distance between the largest intermolecular distance.
Average speed of the trip = 52 km/hr
<h3>Further explanation </h3>
Distance is the length traveled by an object within a certain of time .
Average speed = total distance/total amount of time ,
Can be formulated :

Total distance travelled : 1560 km
Total time : 8 hr + 12 hr + 10 hr = 30 hr

The energy can be shown as:
Q = ms dT
Whereas, m is the mass of block
s is specific heat
dT is change in temperature.
Copper block having the lowest specific heat and thus having the higher change in temperature and therefore having the higher final temperature.
Answer:
Molality = 7.5 mol/kg
Explanation:
Given data:
Mass of NH₄Cl = 6.30 g
Mass of water = 15.7 g (15.7/1000 =0.016 kg)
Molality = ?
Solution:
Formula of molality:
Molality = Moles of solute / mass of solvent in gram
Now we will first calculate the number of moles of solute( NH₄Cl )
Number of moles = mass/ molar mass
Molar mass of NH₄Cl = 53.491 g/mol
Number of moles = 6.30 g/ 53.491 g/mol
Number of moles = 0.12 mol
Now we will calculate the molality.
Molality = Moles of solute / mass of solvent in gram
Molality = 0.12 mol / 0.016 kg
Molality = 7.5 m
or (m=mol/kg)
Molality = 7.5 mol/kg