A hydrated salt is found to have the empirical formula CaN2H8O10. What is its dot formula?
please please give me steps so ill be able to do more of them. please explain please
please please give me steps so ill be able to do more of them. please explain please
-
A substance that is hydrated has a formula similar to:
X•nH2O, where X is the salt and it has n molecules of water attached. The term "dot formula" comes from the use of the"•" to show the water attachment. To my knowledge, most salts do not contain hydrogen (or at least I can't think of any off the top of my head).
For your problem then, CaN2H8O10, all of the hydrogen will be found in the hydrating water. Since water is H2O, there will be n = 8/2 = 4 molecules of water. This requires 4 oxygen atoms; the remaining 6 are part of the salt.
Now we have CaN2O6•4H2O. If you look up salts containing calcium you'll find calcium nitrate, Ca(NO3)2. You can also look at the salt ionically. Balancing the charges will put you on the path to Ca(NO3)2.
So your final dot formula is for hydrated calcium nitrate:
Ca(NO3)2•4H2O
X•nH2O, where X is the salt and it has n molecules of water attached. The term "dot formula" comes from the use of the"•" to show the water attachment. To my knowledge, most salts do not contain hydrogen (or at least I can't think of any off the top of my head).
For your problem then, CaN2H8O10, all of the hydrogen will be found in the hydrating water. Since water is H2O, there will be n = 8/2 = 4 molecules of water. This requires 4 oxygen atoms; the remaining 6 are part of the salt.
Now we have CaN2O6•4H2O. If you look up salts containing calcium you'll find calcium nitrate, Ca(NO3)2. You can also look at the salt ionically. Balancing the charges will put you on the path to Ca(NO3)2.
So your final dot formula is for hydrated calcium nitrate:
Ca(NO3)2•4H2O
-
A hydrated salt is found to have the empirical formula CaN2H8O10. What is its dot formula?
1st determine the maximum number of H2O
Water has 2 H atoms and 1 O atom. If the 8 H atoms are in H2O, you need 4 O atoms to have 4 H2O molecules.
The calcium ion is +2, so you need a -2 ion or 2 -1 ions.
2nd determine the negative ion
Now there are 6 O atoms and 2 N atoms. The ratio of O to N = 3 : 1. This is the NO3 -1 ion. So there are 2 NO3 -1 ions.
Ca +2 + 2 NO3-1 + 4 H2O = Ca(NO3)2 * 4 H2O
IF the mass of water is given, determine the mole ratio of H2O to the compound.
Example:
A 25 gram sample of hydrated copper sulfate contains 9 grams of water.
Mass of CuSO4 = 25 – 9 = 16 grams
Moles of H2O = 9 ÷ 18 = 0.5
Moles of CuSO4 = 16 ÷ 159.6 = 0.1
Mole ratio = 5 H2O : 1 CuSO4
CuSO4 * 5 H2O
1st determine the maximum number of H2O
Water has 2 H atoms and 1 O atom. If the 8 H atoms are in H2O, you need 4 O atoms to have 4 H2O molecules.
The calcium ion is +2, so you need a -2 ion or 2 -1 ions.
2nd determine the negative ion
Now there are 6 O atoms and 2 N atoms. The ratio of O to N = 3 : 1. This is the NO3 -1 ion. So there are 2 NO3 -1 ions.
Ca +2 + 2 NO3-1 + 4 H2O = Ca(NO3)2 * 4 H2O
IF the mass of water is given, determine the mole ratio of H2O to the compound.
Example:
A 25 gram sample of hydrated copper sulfate contains 9 grams of water.
Mass of CuSO4 = 25 – 9 = 16 grams
Moles of H2O = 9 ÷ 18 = 0.5
Moles of CuSO4 = 16 ÷ 159.6 = 0.1
Mole ratio = 5 H2O : 1 CuSO4
CuSO4 * 5 H2O