Question

Answer the following

a) How many Oxygen atoms are in 4.08g of Sodium dioxide, NaO₂

b) Calculate the number of particles found in 193.1 grams of Mg(OH)₂

c) A drink recipe calls for 400 grams of sugar, 4 liters of water, and 2 package of flavoring. While gathering the ingredients, the student realizes that there is only 100 grams of sugar available. How can the student sill make the drink so that it has the correct concentration?

They should use ______ L of water and ____ packages of flavoring.

Answer 1

a)

Mass of NaO₂ = 4.08 g

Molar mass of NaO₂ = 55.0 g/mol

Moles of NaO₂ = mass of NaO₂ / molar mass of NaO₂

                         = 4.08 g / 55.0 g/mol

                         = 0.0742 mol

Now, 1 mol of NaO₂ contains 2 mol of O atoms

Therefore, 0.0742 mol of NaO₂ contains = (2 mol/1 mol) x 0.0742 mol = 0.148 mol of O atoms

Now, 1 mol of O atoms = Avogadro's number or 6.02 x 10²³ O atoms

Therefore, 0.148 mol of O atoms = (6.02 x 10²³/1 mol) x 0.148 mol = 8.91 x 10²² O atoms

Hence, the number of O atoms in 4.08 g of Sodium dioxide = 8.91 x 10²²

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b) Question is not clear. What does "the number of particles" mean here? Here, are particles = molecules?

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c)

For 400 g of sugar, 4 L of water are required.

For, 100 g of sugar, the quantity of water is required = (4 L / 400 g) x 100 g = 1 L

For 400 g of sugar, 2 package of flavoring are required.

For, 100 g of sugar, the package of flavoring are required = (2 / 400 g) x 100 g = 0.5

Hence, they should use 1 L of water and 0.5 packages of flavoring.