Answer:
A. CsBr(s)
Explanation:
we will get here compound with the lowest lattice energy
solution
As we know that Lattice energy is always proportional to the charge of ions and it is inversely proportional to the size of ions.
so that by the smallest charge and the largest size give us the lowest lattice energy and that charge and size is express as here as
Charge
Cs (+1), K(+1), Na (+1), Cl(-1), Br(-1), Sr(+2), Ca(+2), O(-2) .......................1
and
Size
Na+ < Ca2+ < K+ < Sr2+ < Cs+, O2- < Cl- < Br- ..........................2
so that here
correct answer is A. CsBr
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol
The rate in m/s is 5.2 * 10^-4 m/s.
<h3>What is the rate in m/s?</h3>
We know that the speed is given as the ratio of the distance covered to the time taken. In this case, we have been told that the rate at which the tide rises is 6.08 ft per hour. We would now need to convert the rate from 6.08 ft per hour to m/s.
Now;
We know that;
1 foot/hour = 8.5 * 10^-5 m/s
6.08 ft per hour = 6.08 ft per hour * 8.5 * 10^-5 m/s/1 foot/hour
= 5.2 * 10^-4 m/s
Learn more about speed:brainly.com/question/28224010
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