Moles Chemistry Unit 7

Front

What is the empirical formula of a compound with 81.82% carbon and 18.18% hydrogen?

Back

C3H8

Front

Which of the following elements exists as a diatomic molecule? (Options: neon, nitrogen, sulfur, potassium)

Back

Nitrogen

Front

What volume does 12.0 grams of Helium occupy at STP?

Back

67.2 L

Front

What is the mass of 0.75 moles of (NH₄)₃PO₄?

Back

111.75 g

Front

What is the number 6.02 x 10²³ called?

Back

Avogadro's number

Front

Define a mole in chemistry.

Back

A mole is a unit that measures the amount of substance, defined as exactly 6.022 x 10²³ particles (atoms, molecules, etc.).

Front

What is the molar mass of water (H₂O)?

Back

18.02 g/mol

Front

How do you calculate the number of moles from mass?

Back

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

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 relationship between moles and volume at STP?

Back

At STP, 1 mole of any gas occupies 22.4 liters.