I really suck at chemistry and my teacher couldn't stay to explain this to me today.
1.- Explain why substances such as alcohol, HCl, HBr, NH3 are highly soluble in water but CH4, Cl2, O2, CO2 have very low solubilities in water.
2.- Describe how you would make 1 Liter of 0.5 Molar solution of CuSO4 (copper sulfate).
1.- Explain why substances such as alcohol, HCl, HBr, NH3 are highly soluble in water but CH4, Cl2, O2, CO2 have very low solubilities in water.
2.- Describe how you would make 1 Liter of 0.5 Molar solution of CuSO4 (copper sulfate).
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1- the key thing to remember is that "like dissolves like." So polar solutes will dissolve in polar solvents and nonpolar solutes will dissolve in nonpolar solvents. Water is a polar solvent, so polar molecules like HCl, NH3, HBr will readily dissolve in it. On the other hand CH4, Cl2, O2, and CO2 are nonpolar molecules and will not readily dissolve in water.
2- to make 1 Liter of 0.5 M CuSO4, you will know that 0.5 molar = 0.5 moles/L. Since you want to make 1 Liter, you multiply 1 L by 0.5 mol/L to get 0.5 mol. So you want to add 0.5 mol of CuSO4 to 1 liter of water. To find out how many grams that is, you want to add up the atomic masses of copper, sulfur, and 4 oxygen atoms, and multiply that number by 0.5 mol.
2- to make 1 Liter of 0.5 M CuSO4, you will know that 0.5 molar = 0.5 moles/L. Since you want to make 1 Liter, you multiply 1 L by 0.5 mol/L to get 0.5 mol. So you want to add 0.5 mol of CuSO4 to 1 liter of water. To find out how many grams that is, you want to add up the atomic masses of copper, sulfur, and 4 oxygen atoms, and multiply that number by 0.5 mol.
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1. Water is a good solvent for ionic substances because water being polar can surround the ions to solvate or hydrate these ions. HCl, HBr are ionic while NH3 combines with water to form NH4+ and also participates in H-bonding with water.
CH4, Cl2,O2 are covalent and very little soluble in water because there is no stabilization through interaction with water. However CO2 is fairly soluble as it reacts withwater to form H2CO3 ( you must have used soda water which is a soln. of CO2 in water).
2. CuSO4.5H2O has a molar mass of 249.5.
To make 0.5 M soln. dissolve 124.75g Hydrated CuSO4 in 1 L water containing a little acid (to prevent hydrolysis)
CH4, Cl2,O2 are covalent and very little soluble in water because there is no stabilization through interaction with water. However CO2 is fairly soluble as it reacts withwater to form H2CO3 ( you must have used soda water which is a soln. of CO2 in water).
2. CuSO4.5H2O has a molar mass of 249.5.
To make 0.5 M soln. dissolve 124.75g Hydrated CuSO4 in 1 L water containing a little acid (to prevent hydrolysis)