The most appropriate answer is C !!
Answer:
Q1. C
Q2 and Q3 are correct.
Explanation:
Since F=ma, and the force is a constant,
for the greatest acceleration, the mass of the ball must be the least.
Thus ball C has the greatest acceleration.
Let's check:
A) F=ma
a=F/m
a= F/68
B) a=F/72
C) a= F/64 (✓)
The smaller the denominator, the larger the value of a.
(Think: 1/2 >1/3)
0.66 M is the accurate molarity of the new solution of volume of 1200 ml.
Explanation:
Data given:
molarity of copper(II) sulphate, Mconc.= 2M
volume of 2M solution taken Vconc. = 400 ml
volume taken for dilution, Vdilute = 1200 ml
molarity of the diluted solution, Mdilute =?
We will use the formula for dilution as
Mconc Vconc = Mdilute x V dilute (conc is concentrated)
putting the values in the equation:
2 x 400 = Mdilute x 1200
Mdilute = 
Mdilute = 0.66 M
When the solution is diluted to the volume of 1200 ml its molarity changes to 0.66 M.
The total mass would be 142.05 g/mol. Since sodium is 22.99 g/mol and there are 2 sodium atoms, it would be 45.98 g/mol. Divide 45.98 by 142.05 and you get 32.37%