Stoichiometry Pre-test

How many elements are in this chemical formula? $$NaHCO_3$$  

What is the total number of atoms in this formula: CaCl₂

What is the total number of atoms in 4H₂O?

(a)  

What is the molar mass of 2CO₂?

What is the correct molar mass for Mg(OH)₂? (Round to two decimal places)

(a)  

Calculate the molar mass of NH₄NO₂. Round to the nearest whole number.

(a)  

Where does the mole ratio come from?

4 NH₃ + 5 O₂ → 4 NO + 6 H₂O

What is the mole ratio of oxygen to water? (a)  

What is the mole ratio of NH₃ to NO? ​ (b)  

What is the mole ratio of NH₃ to oxygen? ​ (c)  

What is the mole ratio of H₂O to NH₃? ​ (d)  

4 FeS + 7 O₂ → 2 Fe₂O₃ + 4 SO₂

Place the numbers in the correct spots to solve this problem: how many moles of FeS will be needed to produce 13.72 moles of Fe₂O₃? (end amount is the answer)