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molecular-formula

# molecular-formula - Simplest formula calculations Q a...

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Simplest formula calculations Q- a compound is found to contain the following % by mass: 69.58% Ba, 6.090% C, 24.32% O. What is the simplest (i.e. empirical) formula? Step 1 : imagine that you have 100 g of the substance. Thus, % will become mass in grams. E.g. 69.58 % Ba becomes 69.58 g Ba. (Some questions will give grams right off, instead of %) Step 2 : calculate the # of moles (mol = g ÷ g/mol) Step 3 : express moles as the simplest ratio by dividing through by the lowest number. Step 4 : write the simplest formula from mol ratios.
Simplest formula: sample problem Q- 69.58% Ba, 6.090% C, 24.32% O. What is the empirical (a.k.a. simplest) formula? 1 : 69.58 g Ba, 6.090 g C, 24.32 g O 2 : Ba: 69.58 g ÷ 137.33 g/mol= 0.5066 6 mol Ba C: 6.090 g ÷ 12.01 g/mol = 0.5070 8 mol C O: 24.32 g ÷ 16.00 g/mol = 1.520 mol O 3 : 4 : the simplest formula is BaCO 3 mol (reduced) mol 1.520 / 0.5066 6 = 3.000 0.5070 8 / 0.5066 6 = 1.001 0.5066 6 / 0.5066 6 = 1 1.520 0.5070 8 0.5066 6 O C Ba

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Mole ratios and simplest formula Given the following mole ratios for the hypothetical compound AxBy, what would x and y be if the mol ratio of A and B were: A = 1 mol, B = 2.98 mol A = 1.337 mol, B = 1 mol A = 2.34 mol, B = 1 mol A = 1 mol, B = 1.48 mol AB 3 A 4 B 3 A 7 B 3 A 2 B 3 1. A compound consists of 29.1 % Na, 40.5 % S, and 30.4 % O. Determine the simplest formula. 2. A compound is composed of 7.20 g carbon, 1.20 g hydrogen, and 9.60 g oxygen. Find the empirical formula for this compound 3. - 6. Try questions 3 - 6 on page 189.
Question 1 1 : Assume 100 g: 29.1 g Na, 40.5 g S, 30.4 g O 2 : Na: 29.1 g ÷ 22.99 g/mol = 1.26 6 mol Na S: 40.5 g ÷ 32.06 g/mol = 1.26 3 mol S O: 30.4 g ÷ 16.00 g/mol = 1.90 mol O 3 : 4 : the simplest formula is Na 2 S 2 O 3 mol (reduced) mol 1.90 / 1.26 3 = 1.50 1.26 3 / 1.26 3 = 1 1.26 6 / 1.26 3 = 1.00 1.90 1.26 3 1.26 6 O S Na For instructor: prepare molecular models

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