We also can use dimensional analysis for solving problems. Significant Figure Review questionsâ€¦. (answers on the next page) Question 1 Give the correct number of significant figures for 4500, 4500., 0.0032, 0.04050 Question 2 Give the answer to the correct number of significant figures: 4503 + 34.90 + 550 = ? Question 3 Give the answer to the correct number of significant figures: 1.367 - 1.34 = ? Question 4 Give the answer to the correct number of significant figures: (1.3 x 103)(5.724 x 104) = ? Question 5 Give the answer to the correct number of significant figures: (6305)/(0.010) = ? Challenge Dimensional Analysis Questionâ€¦ How many atoms of hydrogen can be found in 45 g of ammonia, NH3? We will need three unit factors to do this calculation, derived from the following information: 1. 1 mole of NH3 has a mass of 17 grams. (1 mole of NH3 = 17 grams NH3) . 2. 1 mole of NH3 contains 6.02 x 1023 molecules of NH3. (1 mole of NH3 = 6.02 x 1023 molecules of NH3) 3. 1 molecule of NH3 has 3 atoms of hydrogen in it. (1 molecule of NH3 = 3 atoms of hydrogen ) We also can use dimensional analysis for solving problems. Answers: (1) 2, 4, 2, 4 (2) 5090 (3 significant figures - round to the tens place - set by 550) (3) 0.03 (1 significant figure - round to hundredths place) (4) 7.4 x 107 (2 significant figures - set by 1.3 x 103) (5) 6.3 x 105 (2 significant figures - set by 0.010)

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# Significant_Figure_Review_questions