Epsom salts, a strong laxative used in veterinary medicine, is a hydrate, which means that a certain number of water molecules are included in the solid structure. The formula for Epsom salts can be written as \(\mathrm{MgSO}_{4} \cdot x \mathrm{H}_{2} \mathrm{O}\), where x indicates the number of moles of \(\mathrm{H}_{2} \mathrm{O}\) per mole of \(\mathrm{MgSO}_{4}\). When 5.061 g of this hydrate is heated to \(250^{\circ} \mathrm{C}\), all the water of hydration is lost, leaving 2.472 g of \(\mathrm{MgSO}_{4}\). What is the value of x ?
Text Transcription:
MgSO4 \cdot xH2O
H2O
MgSO4
250^{\circ} C
Step 1 of 5) Epsom salts, a strong laxative used in veterinary medicine, is a hydrate, which means that a certain number of water molecules are included in the solid structure. The formula for Epsom salts can be written as MgSO4⋅xH2O, where x indicates the number of moles of H2O per mole of MgSO4. When 5.061 g of this hydrate is heated to 250∘C, all the water of hydration is lost, leaving 2.472 g of MgSO4. What is the value of x Interconverting Molarity, Moles, and Volume If we know any two of the three quantities in the definition of molarity (Equation 4.31), we can calculate the third. For example, if we know the molarity of an HNO3 solution to be 0.200 M, which means 0.200 mol of HNO3 per liter of solution, we can calculate the number of moles of solute in a given volume, say 2.0 L. Molarity therefore is a conversion factor between volume of solution and moles of solute: Moles HNO3 = 12.0 L soln2a 0.200 mol HNO3 1 L soln b = 0.40 mol HNO3 To illustrate the conversion of moles to volume, let’s calculate the volume of 0.30 M HNO3 solution required to supply 2.0 mol of HNO3:
