Question

PLEASE HELP ASAP!

Answer 1

Answer:

$\large \boxed{\text{D. 710 g}}$

Explanation:

1. Calculate the molar mass of Na₂SO₄

$\begin{array}{ccc}\textbf{Atoms} &\textbf{M}_{\textbf{r}} & \textbf{Mass/u}\\\text{2Na} & 23 & 46\\\text{1S} & 32 & 32\\\text{4O}&16 & 64\\&\text{TOTAL =} & \mathbf{142}\\\end{array}$

The molar mass of Na₂SO₄ is 142 g/mol.

2. Calculate the moles of Na₂SO₄

$\text{Moles of Na _{2} SO}_{4} = \text{2.5 L solution} \times \dfrac{\text{2.0 mol Na _{2} SO}_{4}}{\text{1 L solution}} = \text{5.0 mol Na _{2} SO}_{4}$

3. Calculate the mass of Na₂SO₄

$\text{Mass of Na _{2} SO}_{4} = \text{5.0 mol Na _{2} SO}_{4} \times \dfrac{\text{142 g Na _{2} SO}_{4}}{\text{1 mol Na _{2} SO}_{4}} = \text{710 g Na _{2} SO}_{4}\\\\\text{You need } \large \boxed{\textbf{710 g}} \text{ of Na _{2} SO}_{4}$