Mole Calculation - empirical formula and molar mass

What is the mass of 2 moles of carbon dioxide (CO₂)?

• 75.36 g

• 88.02 g

• 102.50 g

• 44.01 g

In the reaction 2H₂ + O₂ -> 2H₂O, how many moles of water are produced from 4 moles of oxygen with excess hydrogen?

• 8 moles

• 10 moles

• 4 moles

• 6 moles

What is the empirical formula of a compound that contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen?

• C₂H₃O₂

• CH₃O

• C₄H₆O₂

• C₃H₄O₃

How many grams of sodium hydroxide (NaOH) are needed to react completely with 2 moles of hydrochloric acid (HCl) according to the equation 2NaOH + HCl -> NaCl + H₂O?

• 50 grams of NaOH

• 100 grams of NaOH

• 80 grams of NaOH

• 120 grams of NaOH

What is the molar mass of calcium phosphate (Ca₃(PO₄)₂)?

• 205.12 g/mol

• 410.36 g/mol

• 125.09 g/mol

• 310.18 g/mol

In the reaction 4NH₃ + 5O₂ -> 4NO + 6H₂O, what is the theoretical mass of ammonia (NH₃) required to produce 8 moles of water?

• 2

• 10

• 4

• 6

What is the mass of 3 moles of sulphuric acid (H₂SO₄)?

• 200.12 g

• 294.24 g

• 100.56 g

• 450.32 g

What is the empirical formula of a compound that contains 25.9% nitrogen and 74.1% oxygen?

• NO₃

• N₂O

• NO

• NO₂

What is the empirical formula of a compound that contains 20% nitrogen, 6.7% hydrogen, and 73.3% oxygen?

• NH₃

• N₂H₃O

• NH₂O

• NH₄NO₃

How many moles of oxygen are required to completely react with 24.3 g of magnesium according to the equation 2Mg + O₂ -> 2MgO?

• 0.5 moles

• 0.33 moles

• 2 moles

• 0.66 moles