Question

A sample of As weighs 73.2 grams. Will a sample of Kr that contains the same number of atoms weigh more or less than 73.2 grams? (more, less): Calculate the mass of a sample of Kr that contains the same number of atoms. grams of Kr

Answer 1

Answer:

This means a sample of 73.2 grams As atoms weighs less than the same amount of Kr atoms

Explanation:

Step 1: Data given

Mass of As = 73.2 grams

Molar mass As = 74.92 g/mol

Molar mass of Kr = 83.80 g/mol

Step 2: Calculate moles As

Moles As = Mass As / molar mass As

Moles As = 73.2 grams . 74.92 g/mol

Moles As = 0.977 moles

Step 3: Calculate As atoms

As atoms = moles As * number of Avogadro

As atoms = 0.977 moles * 6.02 * 10^23

As atoms = 5.88 *10^23 As atoms

Step 4: Calculate moles Kr

Moles Kr = Atoms Kr / number of Avogadro

Moles Kr = 5.88 * 10^23 Kr atoms / 6.02 *10^23

Moles Kr = 0.977 moles

Step 5: Calculate mass Kr

Mass Kr = moles Kr * molar mass Kr

Mass Kr = 0.977 moles * 83.80 g/mol

Mass Kr = 81.9 grams

This means a sample of 73.2 grams As atoms weighs less than the same amount of Kr atoms