IG Chemistry-5 Chemical calculation (5.1)

What is the definition of a mole in chemistry?

• A mole is a type of chemical reaction in which two substances combine to form a new substance.

• A mole is a unit of measurement in chemistry that represents the amount of a substance.

• A mole is a unit of measurement in chemistry that represents the volume of a substance.

• A mole is a small, furry animal commonly found in gardens.

Calculate the number of moles in 25 grams of water (H2O).

• 1.387

• 5.0

• 2.5

• 0.5

What is the total number of atoms in 1.0 mole of CO₂?

• 1.5 x 10²³
• 12 x 10²³
• 3 x 10²³
• 18 x 10²³

What is the mass percent composition of Benzene, C₆H₆?

• C = 50%

  H = 50%

• C = 85.7 %

  H = 14.3%

• C = 92.3%

  H = 7.7%

• C = 71.9%

  H = 28.1%

What is the molecular formula if the empirical formula is C₂H₅ and the molecular molar mass is 58.14 g/mol?

• C₂H₅
• C₄H₁₀
• C₁H_2.5
• C₄H₈

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements. (keep two decimal places throughout calculations)

• SO
• SO₂
• SO₃
• SO₄

How many grams is 1.2 moles of Neon?

• 0.05 grams
• 16.6 grams
• 21.2 grams
• 24 grams

Tags

NGSS.HS-PS1-7

How many moles of magnesium are in 3.01x10²² atoms of magnesium?

• 5.00x10⁴⁴ moles Mg
• 0.050 moles Mg
• 1.81x10⁴⁶ moles Mg
• 5 moles Mg

The molar mass of an element is equal to its...

• Atomic mass
• Atomic number
• Oxidation number
• Valence electrons

How many particles are in a mole?

• 602
• 602 million
• 602 moles
• 6.02 x 10²³