Calculate the total moles of ions in 30.4 g FeBr₃.

Calculate the mass (g) of a sample containing 8.45 x 10²³ molecules of melatonin (C₁₃H₁₆N₂O₂).

A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds to form a closed structure, with fused rings of five to seven atoms. Buckminsterfullerene is a type of fullerene with a molecular formula of C₆₀. The density of C₆₀ is 1.65 g/cm³. Assuming a perfect sphere that is 100 nm in diameter formed by this molecule such that the space between molecules can be neglected, calculate the approximate number of C atoms contained in one sphere of this size.

A metal cube made out of pure iron has a side length of 3.50 cm. Iron has a density of 7.874 g/cm³ at room temperature. Calculate the number of iron atoms in the cube.

Constantan is a copper-nickel alloy containing 55.0 % copper and 45.0 % nickel. The density of the alloy is 8.885 g/cm³. A sphere made from constantan has a volume of 58.5 cm³. Calculate the number of copper and nickel atoms in the sphere.

Calculate the number of P atoms in 2.63 g of phosphorus pentabromide (PBr₅)

Calculate the mass in grams of Br 3.28 x 10²¹ molecules of PBr₅

How many molecules of phenol (C₆H₅OH) are present in 248 mL of phenol? The density of phenol is 1.07 g/cm³.