Question

How many moles of ions will be present in 716 ml of 0.450 m solution of sodium phosphate(aq)?

Answer 1

0.644 moles First, calculate the number of moles of sodium phosphate by multiplying volume times molarity. 0.716 l * 0.450 mol/l = 0.3222 mol When dissolved in water, sodium phosphate breaks up into 2 ions, so the number of ions is 2 * 0.3222 mol = 0.6444 mol So there will 0.644 moles of ions present.

Answer 2

Answer: Number of moles of ions in 0.716 L of 0.450 M solution is 1.2888 moles.

Solution:

$Na_3PO_4(aq)\rightarrow 3Na^+(aq)+PO_4^{3-}(aq)$

Volume of the solution 716 mL

Molarity of the solution : 0.450 M

$Molarity=\frac{\text{Number of moles}}{\text{Volume in Liters}}$

$0.450 mol/L=\frac{\text{Number of moles of }Na_3PO_4}{0.716 L}$

$\text{Number of moles of }Na_3PO_4=0.450mol/L\times 0.716=0.3222 moles$

According to reaction one mol $Na_3PO_4$ is giving 4 moles of ions.

Number of moles of ions in 0.716 L of 0.450 M solution is = $4\times 0.3222=1.2888 moles$

Hence,number of moles of ions in 0.716 L of 0.450 M solution is 1.2888 moles.