Step-by-step explanation:
First, let's find the quantity in moles of Na there are in 4.5 liters of a 1.5 M Na solution. For this, we use the following formula:
M = n/V
M = molarity
n = moles
v = volume
in this case we have:
M = 1.5
V = 4.5
n = ??
n = 1.5 * 4.5
n = 6.75 moles
now let's transform to grams using the following formula:
mass = moles * molar mass
molar mass of Na = 23 g/mol
So:
mass = 6.75 * 23
mass = 155.25 g
Answer: mass of Na = 155.25 g
155.3 g (4 sig fig)
155 (3 sig fig)