Name: _____________________ Date: ____________ HYDRATE PROBLEMS 1. A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate? 2. A hydrate of Na2CO3 has a mass of 4.31 g before heating. After heating, the mass of the anhydrous compound is found to be 3.22 g. Determine the formula of the hydrate and then write out the name of the hydrate. 3. A 1.98 g sample of a cobalt(II) chloride hydrate is heated over a burner. When cooled, the mass of the remaining dehydrated compound is found to be 1.55 g. 4. A 5.00 g sample of hydrated barium chloride, BaCl2 ∙ nH2O, is heated to drive off the water. After heating, 4.26 g of anhydrous barium chloride, BaCl2, remains. What is the value of n in the hydrate’s formula? 5. Given that the molar mass of Na2SO4 ∙ nH2O is 322.1 g/mol, calculate the value of n. 6. Anhydrous lithium perchlorate (4.78 g) was dissolved in water and recrystalized. Care was taken to isolate all the lithium perchlorate as its hydrate. The mass of the hydrated salt obtained was 7.21 g. What hydrate is it? 7. A 20g sample of a hydrate of nickel sulfate (NiSO4) lost 9.63g of water when heated. Determine the hydrate’s formula. 8. A hydrate containing copper, sulfur, oxygen, and water lost 9g upon heating. Originally the hydrate had weighed 25g. Analysis of the anhydrous substance revealed that the 6.4g of Cu, 3.2g of S, and 6.4g of O were present. Find the formula of the hydrate. 9. A substance was found to have the following percentages by mass: 23% zinc; 11% sulfur; 22% oxygen; 44% water. What is the empirical formula? 10. A hydrate of magnesium sulfate has a mass of 13.52 g. This sample is heated until no water remains. The MgSO4 anhydrate has a mass of 6.60 g. Find the formula and name of the hydrate. 11. A sample of copper (II) sulfate hydrate has a mass of 3.97 g. After heating, the CuSO4 that remains has a mass of 2.54 g. Determine the correct formula and name of the hydrate. 12. When 5.00 g of FeCl3 ∙ xH2O are heated, 2.00 g of H2O are driven off. Find the chemical formula and the name of the hydrate. 1 Name: _____________________ Date: ____________ 13. […]
