Date 5/1/13 Mole to Mole, Mole to Gram By: Keenan Reardon. Wednesday, May 1, 13
Date 5/1/13
Mole to Mole, Mole to GramBy: Keenan Reardon.
Wednesday, May 1, 13
Question 1 Mole to Mole
✤ Start with a balanced equation
✤ N2 + 3 H2 ---> 2 NH3
Wednesday, May 1, 13
Question 1
✤ if we have 2.00 mol of N2 reacting, how many moles of NH3 will be produced?
Wednesday, May 1, 13
Process 1
✤ Look at the ratios
✤ N2 + 3 H2 ---> 2 NH3
✤ 2.00 mol of N2-->?molNH3
Wednesday, May 1, 13
Answer 2
✤ In the balanced equation for every mole ofnitrogen there were 2 NH3’s so if we have 2 moles of nitrogen then we would need 4 molNH3
✤ =4mol NH3
Wednesday, May 1, 13
Question 2 Mole to Mole
✤ Suppose 6.00 mol of H2 reacted. How many moles of ammonia(NH3) would be produced?
Wednesday, May 1, 13
Answer 2
✤ This again is about ratios.
✤ N2 + 3 H2 ---> 2 NH3
✤ The Hydrogen ammonia ratio is 3/2
✤ Since we have 6 moles of hydrogen then we would need 4 moles of NH3
✤ =4molNH3
Wednesday, May 1, 13
Question 3 Mole to Mole
✤ We want to produce 2.75 mol of NH3. How many moles of nitrogen would be required?
Wednesday, May 1, 13
Process
✤ This is tricky so we start with what is given to us.
✤ Which is 2.75 mol of NH3--> ?MolN2
✤ We then would have to use the coefficients and cross multiply, leaving what we want to be left with on top.
Wednesday, May 1, 13
Answer 3
✤ The ratio of the equation is 2/1
✤ We would then cross multiply 2.75/x =2/1
✤ =1.38 mol N2
Wednesday, May 1, 13
Question 1 Mole to Mass
✤ Start with balanced equation.
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Questions 1
✤ 1.50 mol of KClO3 decomposes. How many grams of O2 will be produced?
Wednesday, May 1, 13
Process
✤ 2 KClO3 ---> 2 KCl + 3 O2
✤ Find ratios, KClO3 and O2 is 2/3
✤ 1.50 mol of KClO3--> ?grams O2
✤ Cross multiply - 1.50/x times 2/3
✤ =2.25mol O2
✤
Wednesday, May 1, 13
Answer 1
✤ Now that we have 2.25mol O2 we convert it to grams.
✤ We then multiply 2.25mol O2 by the molar mass of one mole of O2
✤ 2.25mol O2 X 32g O2
✤ =72gO2
Wednesday, May 1, 13
Question 2
✤ We want to produce 2.75 mol of KCl. How many grams of KClO3 would be required?
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Process
✤ Ratios
✤ 2/2
✤ So we know that we are gonna use the same amount of moles, all we have to do now is convert it to grams
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Answer
✤ 2.75mol KClO3 X 122.55g KCLO3
✤ =337g KCLO3
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Question 3
✤ If 80.0 grams of O2 was produced, how many moles of KClO3 decomposed?
✤ Different question, but same process, only difference if it is backwards.
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Process
✤ Find Ratio
✤ O2 to KCLO3 is 3/2
✤ we then divide 80.0 grams of O2 by the molar mass of O2
✤ 80/32 = 2.50molO2
✤ 2 KClO3 ---> 2 KCl + 3 O2
Wednesday, May 1, 13
Answer 3
✤ Now we cross multiply 2.50/x = 3/2
✤ This equals 1.67 molKClO3
✤ 2 KClO3 ---> 2 KCl + 3 O2 ✤ 80/32 = 2.50molO2
Wednesday, May 1, 13