Question

2.00 L of 0.800 M `NaNO_3` must be prepared from a solution known to be 1.50 M in concentration. How many mL are required?

Answer 1

1066.7mL of the 1.50M solution
or 1070 mL (3 sig figs)

Explanation:

When a solution is diluted the number of moles of solute, n, does not change so:

`n_"initial" = n_"final"`
or
`C_"initial" xx V_"initial" = C_"final" xx V_"final"`

`C_"initial" = 1.50 M`
`V_"initial" = ? mL`
`C_"final" = 0.800 M`
`V_"final" = 2.00 L = 2000 mL`

`V_"initial" = (C_"final" xx V_"final")/ C_"initial"`

`V_"initial" = (0.800 xx 2000)/ 1.50`

`V_"initial" = 1066.67 mL`