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n a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B. 2A⟶3B How many molecules of substance B are produced when 27.6 g of substance A reacts? The molar mass of substance A is 27.8 g/mol. Step 1: Convert the mass of A to moles. moles of A: mol Step 2: Convert the number of moles of A to the number of moles of B. moles of B: mol Step 3: Convert the number of moles of B to molecules of B. molecules of B:

User Alex Cheng
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Answers:

  • Step 1: Convert the mass of A to moles. moles of A: 0.993 mol

  • Step 2: Convert the number of moles of A to the number of moles of B. moles of B: 1.49 mol

  • Step 3: Convert the number of moles of B to molecules of B. molecules of B: 8.97 × 10²³ molecules

Step-by-step explanation:

1) Chemical equation (given):

  • 2A⟶3B

2) Follow the given steps:

Step 1: Convert the mass of A to moles.

moles of A:

  • n = mass in grams / molar mass

  • n = 27.6 g / 27.8 g/mol = 0.993 mol of A

Step 2: Convert the number of moles of A to the number of moles of B.

  • Stoichiometric ratio:

2 mol A : 3 mol B

  • Proportion:

2 mol A / 3 mol B = 0.993 mol A / x

⇒ x = 0.993 mol A × 3 mol B / 2 mol A = 1.49 mol of B

Step 3: Convert the number of moles of B to molecules of B.

  • Avogadro's number: 6.022 × 10²³ molecules / mol

  • 1.49 mol × 6.022 × 10²³ molecules / mol = 8.97 × 10²³ molecules of B.
User Julien Berthoud
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