What is the total number of moles of nacl(s) needed to make 3.0 liters of a 2.0 m nacl solution?
(1) 1.0 mol (3) 6.0 mol
(2) 0.70 mol (4) 8.0 mol

The number of moles of NaCl(s) needed to make 3.0 L of a 2.0 M NaCl solution (soln) is:
3.0 L NaCl soln* (2.0 mol NaCl/ 1L NaCl soln)= 6.0 mol NaCl.

Therefore, (3) 6.0 mol is the correct answer.

Hope this helps~

The big advantage to using continuous compounding to express growth rates is it avoids the problem of asymmetry in growth rates:

For example, if we use the normal definition and $100 grows to $105 in one time period, that's a growth rate of $105/$100 - 1 = 5% But if $105 decreases to $100, that's a growth rate of $100/$105 - 1 = -4.76%

The problem of asymmetry is those two growth rates, 5% and -4.75% are not equal up to a sign.

But if you use continuous compounding the growth rate in the first case is ln(105/100) = 0.04879.
And the growth rate in the second is ln (100/105) = -0.04879.
Those two growth rates are definitely the negative of each other.