How many O 2 molecules are present in 0.470 g of oxygen gas? Strategy Plan STEP 1:

How many O₂ molecules are present in 0.470 g of oxygen gas?

Transcribed Image Text:

Strategy Plan STEP 1: What unit is asked for in the answer? STEP 2: What given value is related to the answer? STEP 3: What unit factor(s) should we apply? The molar mass from the periodic table is 32.00 g O₂ = 1 mol O₂, and by definition, 1 mol O₂ = 6.02 × 1023 molecules O₂. Thus, the two pairs of unit factors are shown in Step 3. Unit Analysis Map given value 0.470 g 0₂ X unit factor 1 1 mol O₂ 32.00 g 0₂ Step 1: Step 2: Step 3: molecules O₂ X 1 mol O₂ 32.00 g 0₂ 0.470 g 0₂ 1 mol O₂ 6.02 x 1023 molecules O₂ or or unit factor 2 6.02 x 1023 molecules O2 1 mol O₂ 32.00 g 0₂ 1 mol O₂ 6.02 x 1023 molecules O₂ 1 mol O₂ unit in answer = ? molecules O₂