Question

A hydrate is determined to be 45.43% water and 54.57% CoCl2. Find the chemical formula and name for this hydrate. (Hint – Assume that there is 100 g total of hydrate compound.):

A. Calculate the moles of water and CoCl2 in the hydrate.
B. Determine the chemical formula of the hydrate.
C. Analyze the molar ratios in the hydrate compound.
D. Discuss

Answer 1

To find the chemical formula for a hydrate with 45.43% water and 54.57% CoCl2, calculate moles of each component and use molar ratios to determine the hydrate's formula, which may be cobalt (II) chloride hexahydrate if the molar ratio is 6:1.

Step-by-step explanation:

To calculate the chemical formula and name for a hydrate that is 45.43% water and 54.57% CoCl2, assume there are 100 g of the hydrate compound:

Calculate the moles of water and CoCl2: The mass of water (H2O) in the hydrate is 45.43 g, and the mass of CoCl2 is 54.57 g. Use their molar masses to find the moles of each component.

Determine the chemical formula of the hydrate: The molar ratio of CoCl2 to H2O gives the subscript numbers for the formula.

Analyze the molar ratios: Divide the moles of each component by the smallest number of moles to simplify the ratio to whole numbers, which may indicate the formula of the hydrate.

For instance, if the molar ratio of water to CoCl2 is determined to be 6:1, the chemical formula is CoCl2·6H2O, named cobalt (II) chloride hexahydrate.