CHM 1210 Opotowsky Lecture Videos UNIT Dimensional Analysis PDF

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Taught by Joelle Opotowsky online through Blackboard...

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CHM 1210 OPOTOWSKY LECTURE VIDEOS

UNIT DIMENSIONAL ANALYSIS Calculate the # of moles in 2.00g Aluminum Foil 1. Determine sig figs: 3 sig figs due to the trailing zeroes 2. Set up presentation line a. What do they want? What is the goal of the problem? b. Most important to set up a line in order to communicate the problem 3. Include number, units, substance or else NO POINTS WILL BE GIVEN >:c Givens: 2.00g Al, g, moles moles: 2. 00𝑔 𝐴𝑙 ×

1 𝑚𝑜𝑙𝑒 𝐴𝑙 = 26.98𝑔 𝐴𝑙

0.074178m → 0.0741 mole Al

Calculate the number of moles of H2O produced when 2.00g oxygen gas reacts with excess hydrogen gas. -Opotowsky assumes we know her diatomic molecules H2(g): Hydrogen gas, O2(g): Oxygen gas ● Allowed to use coefficient space to balance the equations. ● Ask yourself what are the units for the balanced equations? ● Understand the chemical equations as a recipe being done. _ H2(g) + _ O2(g) → _ H2O (l) Mole mole mole 2.00g ? moles ? moles H2O= 2. 00𝑔 𝑂2 ×

---> 2 H2(g) + 1 O2(g) → 2 H2O (l) (complete equation)

1 𝑚𝑜𝑙𝑒 𝑂2 32.00𝑔 𝑂2

×

2 𝑚𝑜𝑙𝑒 𝐻2𝑂 1 𝑚𝑜𝑙𝑒 𝑂2

= 0.125 mole → 0.125 mol H2O

Things that we knew in order to set up the equation: 1) 2.00 g O2 2) g→ moles (O2: 2 x 16= 3)

1 𝑚𝑜𝑙𝑒 𝑂2 2 𝑚𝑜𝑙𝑒 𝐻2𝑂

32.00𝑔 1 𝑚𝑜𝑙𝑒 𝑂2

)

(For everyone one mole of oxygen, this would produce 2 moles water)...