Intro to Stoichiometry

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

• Write a Balanced Equation

• Calculate the number of moles

• Calculate the molar mass

• Determine the mole ratios

Balance the following reaction :

CaCl₂(s) + H₂O(l) --> HCl(g) + Ca(OH)₂(aq)

• 1,2,2,1

• 1,2,1,1

• 2,1,1,1

• 2,1,2,1

Tags

NGSS.HS-PS1-7

Which of the following dimensional analysis setups will correctly convert 4.00x10²³atoms of cobalt to moles of cobalt? How many moles of colbalt are there?

• setup B : 0.6644mol Co
• setup A: 2.41x10⁴⁷mol Co
• setup A : 0.664mol Co
• setup B: 2.41x10⁴⁷mol Co

Which one of the following have the greatest mass?

• 1 mole carbon
• 2 mole Hydrogen
• 1 mole silver
• 1 mole gold

What are the units for molar mass?

• grams
• amu
• grams/mole
• liters

Tags

NGSS.HS-PS1-7

What is the molar mass of Ca(OH)₂

• 74.1 g/mol
• 210.0g/mol
• 98.9g/mol
• 219.9g/mol

How do you go from grams to moles?

• divide by molar mass

• multiply by molar mass

• divide by avogadro's number

• multiply by avogadro's number

How many moles are in 45.6 g Ca?

• 0.879mol Ca

• 1.14mol Ca

• 1.50mol Ca

• 0.62 mol Ca

How many grams are in 10.2 moles of NaCl?

• 597grams

• 5.74 grams

• 579 grams

• 7.65 grams

Consider the balanced equation: 
Na₂SIO₃(s) + 8HF(aq) --> H₂SiF₆ (aq) + 2NaF(aq) + 3H₂O(l)
If 9 moles of water are produced at the end of the reaction, how many moles of hydrofluoric acid were used?

• 24 moles
• 3.375 moles
• 3 moles
• .375 moles

Tags

NGSS.HS-PS1-7