Chemistry Exam Review #2

Front

How many moles are in 59.6 grams of BaSO4?

Back

0.256 mole

Front

What is the percent by mass of iron in the compound Fe2O3?

Back

70%

Front

What is a unique characteristic of the bonding between metal atoms?

Back

Delocalized electrons move among many atoms creating a sea of electrons.

Front

According to the equation 2H2O (l) → 2H2 (g) + O2 (g), what mass of H2O is required to yield 22.4 L of O2 at STP?

Back

36 g

Front

How many molecules are contained in 55.0 g of H2SO4?

Back

3.38x10^23 molecules

Front

What is the molar mass of BaSO4?

Back

233.39 g/mol

Front

Define percent by mass in a compound.

Back

Percent by mass is the mass of a component divided by the total mass of the compound, multiplied by 100.

Front

What is STP in chemistry?

Back

STP stands for Standard Temperature and Pressure, defined as 0°C (273.15 K) and 1 atm pressure.

Front

What is the formula to calculate the number of moles?

Back

Number of moles = mass (g) / molar mass (g/mol).

Front

Explain the concept of a 'sea of electrons' in metallic bonding.

Back

In metallic bonding, electrons are not bound to individual atoms but are free to move throughout the metal, creating a 'sea' of delocalized electrons.