4. FUN with STOICHIOMETRY!!! Balancing chemical equations Ratio and Proportion Limiting Reagent All You Know About Stoichiometry
5.
6. Which one would you pick??? ( yellow / red ) Zn + HCl ---> ZnCl 2 + H 2 Zn + 2HCl ---> ZnCl 2 + H 2 (keep your choice in your mind…you might want to change your choice later )
22. Mary was home alone…. She was craving for pancakes … She remembered that her mum always kept a stock of pancake mixture in the kitchen … She grabbed the box... And started reading the instructions…
23. This is what the instruction said… 4 cups of mixture 2 cups of water 4 eggs Mix all, Beat well!!! Note : Each pack makes 12 large pancakes
24. But 12 is too many!!! She wanted only 3… Hmm…can you help her with the pancake mixture?
25. 4 cups of mixture 2 cups of water 4 eggs 12 pancakes ?eggs 3 pancakes ? cups of mixture ? cups of water Can you help her with the correct measurements to make just 3 pancakes???
26.
27.
28. 4 cups of mixture 2 cups of water 4 eggs 12 pancakes ?eggs 3 pancakes ? cups of mixture ? cups of water 1 egg 3 pancakes 1 cup of mixture ½ cup of water ÷4 ÷4 ÷4 ÷4
29. The pancakes turned out so well for a first timer…Mary loved it !!! THANK YOU!
30. Can you apply the same idea here??? 1 mole of hydrochloric acid react with 1 mole of Sodium hydroxide solution to form 1 mole of sodium chloride and 1 mole of water. Can you figure out how many moles of water will be produced if 0.5 mole of acid is used???
31.
32.
33.
34. One final task before getting started!!! Explore the reagents and the apparatus provided in the virtual lab… Explore your virtual lab!!! Get familiarized with it…
35. Get your task sheet and get going with your virtual lab… You are suppose to complete the task given using your virtual lab tools Get the word document ‘ FUN WITH VIRTUAL LAB’ http://www.scribd.com/doc/66347972
67. HCI + NaOH NaCI +H 2 O V= 50cm 3 M=1.0mol/ dm 3 V= 25cm 3 M=1.0mol/ dm 3 Mass=? How would you determine what is the maximum mass of sodium chloride that can be produced ?
68.
69. Inspect the equation to check if it was balance Calculate the number of mole of the reactants given to you Determine the limiting reagent Calculate the maximum mass of sodium chloride that can be obtained
89. Interpret the question to form a chemical equation Recognize unbalanced and balanced reaction equations Balance the unbalanced equation Explain excess and limiting reagent Calculate the mass of the yield
93. Interpret the question to form a chemical equation 25g of sodium chloride reacts with 50cm 3 of silver nitrate solution with the concentration of 1.0 mol dm -3 . What is the maximum amount of silver chloride produced? Which one is the limiting reagent? NaCI + AgNO 3 AgCI + NaNO 3
94. Recognize unbalanced and balanced reaction equations NaCI + AgNO 3 AgCI + NaNO 3 Na Cl Ag 1 1 1 1 1 1 NO 3 1 1 BALANCED
95.
96.
97.
98.
99. Interpret the question to form a chemical equation In a metal displacement reaction,65g of aluminium reacted with 150g of Iron (ii) Oxide. What will be the excess reagent at the end of the experiment? What needs to be added to maximize the production of Iron? Al + Fe 2 O 3 Al 2 O 3 + Fe
100. Recognize unbalanced and balanced reaction equations Al + Fe 2 O 3 Al 2 O 3 + Fe Al Fe O 1 2 3 3 1 2 UNBALANCED
101. Balance the unbalanced equation Al + Fe 2 O 3 Al 2 O 3 + Fe Al Fe O 1 2 3 3 1 1 BALANCED! X 2 X 2 2Al + Fe 2 O 3 Al 2 O 3 + 2Fe
102.
103. Calculate the mass of the yield No calculation for the amount of yield for this question, but it requires you to decide which reactant needs to be added to maximize the mass of yield Increase the mass of Iron(II) Oxide as it is the limiting reagent in this experiment!
104.
105. Interpret the question to form a chemical equation 50cm 3 of Sodium Hydroxide with the concentration of 0.2mol/dm 3 was used to neutralize 35cm 3 of sulphuric acid with the same concentration. What will be the maximum mass of water produced? Which one is the limiting reagent in the above reaction? NaOH + H 2 SO 4 Na 2 SO 4 +H 2 O
106. Recognize unbalanced and balanced reaction equation NaOH + H 2 SO 4 Na 2 SO 4 +H 2 O Na O H 1 5 3 2 5 2 S 1 1 UNBALANCED
107. Balance the unbalanced equation NaOH + H 2 SO 4 Na 2 SO 4 +H 2 O 2NaOH + H 2 SO 4 Na 2 SO 4 + 2H 2 O Balancing the number of Sodium atoms, oxygen and hydrogen atoms will balance out the other elements…You don’t really have to balance each and everyone of them… BALANCED!
