Final answer:
To calculate the moles of LiBr in 56.8 grams, divide the mass of LiBr by its molar mass (86.844 g/mol) to obtain approximately 0.654 moles.
Step-by-step explanation:
To determine the quantity in moles of LiBr in 56.8 grams of LiBr, you need to know the molar mass of LiBr and use it as a conversion factor. The molar mass of LiBr (Lithium Bromide) can be found by adding the atomic mass of Lithium (Li) which is approximately 6.94 g/mol, and the atomic mass of Bromine (Br), which is about 79.904 g/mol. Thus, the molar mass of LiBr is 6.94 g/mol + 79.904 g/mol = 86.844 g/mol.
Next, you can use the following conversion to find the moles of LiBr:
56.8 g LiBr * (1 mol LiBr / 86.844 g LiBr) = 0.654 moles of LiBr.
This calculation shows that there are roughly 0.654 moles of LiBr in 56.8 grams of the compound.