Stoichiometry

For the reaction represented by the equation Pb\left(NO_3\right)_2+2KI\ \rightarrow\ PbI_2+2KNO_3 how many moles of lead iodide PbI_2 are produced of 300 grams potassium iodide KI when Pb\left(NO_3\right)_2 is in excess?

• 114.78 mol PbI₂

• 0.904 grams PbI₂

• 0.904 mol PbI₂

• 114.78 grams PbI₂

Tags

NGSS.HS-PS1-7

• 408 g KClO₃

• 804 g KClO₃

• 598 g KClO₃

• There is not enough information.

___KNO₃ → ___KNO₂ + ___O₂

What coefficients are needed to balance the reaction?

• 2, 2, 1

• 2, 3, 2

• 1, 2, 2

• 1, 3, 1

Tags

NGSS.HS-PS1-7

What is the first thing you must do to solve a stoichiometry problem?

• Write a Balanced Equation

• Write an Unbalanced Equation

• Panic

• Avogadro's Number

2H₂ + O₂ --> 2H₂O

12 grams of H₂ are reacted with 36 grams of O₂.

What is the limiting reactant?

• Hydrogen

• Oxygen

• Water

• There is not a limiting reactant

Tags

NGSS.HS-PS1-7

2H₂ + O₂ --> 2H₂O

12 grams of H₂ are reacted with 36 grams of O₂.

What is the excess reactant?

• Hydrogen

• Oxygen

• Water

• There is no excess reactant

Tags

NGSS.HS-PS1-7

2H₂ + O₂ --> 2H₂O

12 grams of H₂ are reacted with 36 grams of O₂.

Calculate the amount of excess reactant.

• 4.5 grams

• 7.5 grams

• 12.5 grams

• 36.5 grams

Tags

NGSS.HS-PS1-7

From the reaction: B₂H₆ + 3O₂ -->2 HBO₂ + 2 H₂O What mass of O₂ will be needed to burn 36.1 g of B₂H₆? B₂H₆ = 27.68 g/mol

• 13.8 g O₂

• 3.91 mol of O₂

• 125 g O₂

• 41.7 g O₂

Tags

NGSS.HS-PS1-7

Balance this reaction: ____ RbNO₃ + ____ BeF₂ ----> ____ Be(NO₃)₂ + ____ RbF

• 1,1,1,1

• 1,2,1,1

• 2,1,1,2

• 2,1,2,1

Tags

NGSS.HS-PS1-7

What is a Excess Reagent?

• amount you end with

• what you run out of first

• what you have left over

• what you start with