How many atoms are in a sample of copper with a mass of 18.46 grams?

2. How many formula units are in a sample of salt with a mass of 67.69 grams?

3. How many molecules are in a sample of water with a mass of 44.99 grams?

4. What is the mass in grams of 0.250 moles Mg? 5. How many moles are there in 48.096 grams of sulfur?

6. What is the mass of 24.6 formula units of magnesium oxide?

7. How many molecules of dinitrogen pentoxide are contained in 123.46 grams of dinitrogen pentoxide?

Question

Casey Rivers

Chemistry

3 January, 18:33

How many atoms are in a sample of copper with a mass of 18.46 grams?

2. How many formula units are in a sample of salt with a mass of 67.69 grams?

3. How many molecules are in a sample of water with a mass of 44.99 grams?

4. What is the mass in grams of 0.250 moles Mg? 5. How many moles are there in 48.096 grams of sulfur?

6. What is the mass of 24.6 formula units of magnesium oxide?

7. How many molecules of dinitrogen pentoxide are contained in 123.46 grams of dinitrogen pentoxide?

+5

Answers (1)

Know the Answer?

Mark Roberson · Answer 1

Just solve this by using the molar mass/molecular weight, and the avogadros number in a dimensional analysis

18.46 g Cu x (1 mole/64 g) x (6.022 x 10^23 atoms/1 mole) = 1.74 x 10^23 atoms

67.69 g NaCl x (1 mole/58 g) x (6.022 x 10^23 formula units / 1 mole) = 7.03 x 10^23 formula units

44.99 g H2O x (1 mole/18 g) x (6.022 x 10^23 molecules / 1 mole) = 1.51 x 10^24 molecules

0.250 moles Mg x (24 g/1 mole) = 6 g

48.096 g S x (1 mole/32 g) = 1.5 g