Question

Calculate the mass of Na₂CO3. aH2O required to prepare a 250 ml of a 0,05 M solution assuming that the value of a is 10.

Answer 1

Answer:

3.575grams

Explanations:

From the question, we will need to determine the moles of Na₂CO3. 10H₂O using the formula below;

$moles=molarity\times volume$

Given the following parameters

Molarity = 0.05M

Volume = 250ml = 0.25L

Determine the moles of Na₂CO3. 10H₂O

$\begin{gathered} moles=0.05\times0.25 \\ moles=0.0125moles \end{gathered}$

Determine the Na₂CO3. 10H₂O

$\begin{gathered} Mass=moles\times molar\text{ mass} \\ Mass=0.0125moles\times286\frac{g}{mol} \\ mass=3.575grams \end{gathered}$

Hence the mass of Na₂CO3. 10H₂O required to prepare a 250 ml of a 0.05 M solution is 3.575grams