1. Stoichiometry Problems

2. If 304g of Eu (s) are used how many moles of hydrogen gas are produced? __Eu (s)+ __HF (g)  __EuF 3 (s)+ __H 2 (g) Step 1: Balance the Equation!

3. __Eu (s)+ __HF (g)  __EuF 3 (s)+ __H 2 (g) Eu 1Eu 1 H 11H 2 F 11F 3

4. If 304g of Eu (s) are used how many moles of hydrogen gas are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) Step 2 GFM of any formula listed in the question! Eu (s)  GFM = 152g/mole H 2 (g)  GFM = 2g/mole

5. If 304g of Eu (s) are used how many moles of hydrogen gas are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) Step 3 convert mass to moles If 1 mole of Eu = 152g: = X = 2 mole of Eu (s)

6. If 304g of Eu (s) are used how many moles of hydrogen gas are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) Step 4 determine the mole ratio For every 2 moles of Eu (s) used 3 moles of H 2 (g) are produced. = X = 3 moles of H 2 (g)

7. If 608g of Eu (s) are used how many grams of EuF 3 (s) are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) EuF 3  GFM = 209g/mole Eu  GFM = 152g/mole = x = 4moles of Eu

8. If 608g of Eu (s) are used how many grams of EuF 3 (s) are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) Mole ratio: If 4 moles of Eu are used then: = X = 4 moles of EuF 3

9. If 608g of Eu (s) are used how many grams of EuF 3 (s) are produced? _2_Eu (s)+ _6_HF (g)  _2_EuF 3 (s)+ _3_H 2 (g) If 4 moles of EuF 3 are produced then: = X = 836g of EuF 3