6. Chemical Reactions & Quantities

If a sample of sodium chloride, NaCl, contains 73.1 kg, what is its number of formula units?

Calculate the number of oxygen atoms found in 783.9 g NiCl₂ • 6 H₂O.

If the density of water is 1.00 g/mL at 25°C, calculate the number of water molecules found in 1.50 x 10³ µL of water.

A cylindrical copper wire is used for the fences around a house. The copper wire has a diameter of 0.0750 in. How many copper atoms are found in 5.160 cm piece? The density of copper is 8.96 g/cm³. (V = π • r² • h)

The density of the sun is 1.41 g/cm³ and its volume is 1.41 x 10²⁷ m³. How many hydrogen molecules are in the sun if we assume all the mass is hydrogen gas?

What is a mole?

What is Avogadro's number?

Which weighs more, 5.00 g or 0.0225 mol of acetaminophen (C₈H₉O₂)?

Calculate the mass, in grams, for each of the following:

e. 2.08 moles of (NH₄)₂SO₄

Calculate the mass, in grams, for each of the following:

d. 0.145 mole of C₂H₆O

How many Na⁺ ions are in a mole of Na₂SO₄? How many SO₄^2- ions?

How many moles of ions are in 1.75 mol of K₂SO₄?

Caffeine has the formula C₈H₁₀N₄O₂. If an average cup of coffee contains approximately 125 mg of caffeine, how many moles of caffeine are in one cup?

Find the mass in atomic mass units of the following:

a. 1 O atom, with a mass of 2.66 × 10^-23 g

b. 1 Br atom, with a mass of 1.31 × 10^-22 g

The principal component of many kidney stones is calcium oxalate, CaC₂O₄. A kidney stone recovered from a typical patient contains 8.5 × 10²⁰ formula units of calcium oxalate. How many moles of CaC₂O₄ are present in this kidney stone? What is the mass of the kidney stone in grams?