Ch Mole

What is the mass, in grams, of 4.725 mole of aluminum oxide Al₂O₃?{Al = 27, O = 16}

• 964 g

• 1928 g

• 482 g

How many moles of iron (III) oxide are contained in 276 g of pure Fe₂O₃? {Fe = 56, O = 16}

• 0.57 moles

• 3.42 moles

• 1.71 moles

states that “equal volumes of gases at the same temperature and pressure contain equal numbers of particles”.

• Avogadro's hypothesis

• Bohr's hypothesis

• Newton's hypothesis

Standard temperature and pressure (STP) mean

• A temperature of 0°C and a pressure of 101.3 kPa, or 1 atmosphere (atm).

• A temperature of 0°K and a pressure of 10 atmosphere (atm).

• A temperature of 100°C and a pressure of 101.3 kPa, or 1 atmosphere (atm).

At STP, 1 mol, or representative particles, of any gas occupies a volume of......................

• 24.4 L

• 22.4 L.

• 44.2 L

The quantity, 22.4 L, is called the ........................ of a gas.

• molar volume

• Atomic volume

• molar mass

Determine the volume, in liters, of 1.2 mole SO₂ gas at STP.

• 13 L

• 6.5 L

• 26 L

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013

• %Cu= 35.946 %S= 64.054

• %Cu= 79.854 %S= 20.145

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃

• MgN

• Mg₃N₂

What is the percentage of oxygen in carbon dioxide? (CO2)

• 27.3%

• 72.7%

• 30%