Analía Bellizzi – Chemistry Classes

Ronald Reagan High School

IGCSE – THE MOLE – CLASSWORK

IMPORTANT: SHOW YOUR WORK USING WITH PROPORTIONS OR DIMENSIONAL ANALYSIS

A-Calculate the following molar masses:

  1.   Copper (II) Nitrate. Cu(NO3)2  
  2.   Dinitrogen trioxide – N2O3  
  3.   Phosphoric acid. H3PO4 
  4.   Potassium Sulfate. K2SO4 
  5.   Epson Salts (MgSO4•7H2O) 

B-Calculate the mass in grams contained in the quantities specified:

  1.    3 moles of sulfur – S 
  2.    2 moles of silicon – Si 
  3.    0.01 moles of lead (II) iodide. – PbI2 
  4.    20 moles of hydrochloric acid – HCl 
  5.    0.1 moles of Cobalt(II) Chloride hexahydrate (CoCl2•6H2O

C-Calculate the moles contained in the following masses

  1.   4 g of sodium hydroxide – NaOH 
  2.   8 g of water – H2
  3.   585 g of sodium chloride NaCl 
  4.   64 g of methane gas CH
  5.   25 g of Copper sulfate pentahydrate (CuSO4•5H2O)

D-Calculate the number of particles specified in the following exercises:

  1.   Atoms in 1.2 g of C  
  2.   Atoms in 320 g of O  
  3.   Molecules in 7.1 of Cl2   
  4.   Molecules in 54 g of H2O  
  5.   Molecules in 29.4 g of H3PO4  

ANSWERS:

Calculate the following molar masses:

  1.    Ans: 188
  2.    Ans: 76
  3.   Ans: 98
  4.  Ans: 174
  5.  Ans: 246

Calculate the mass in grams contained in the quantities specified:

  1.   Ans: 96g
  2.    Ans: 56g
  3.   Ans: 4.61g
  4.   Ans: 730g
  5.    Ans: 23.8g

Calculate the moles contained in the following masses

  1.   Ans:  0.1 mol
  2.   Ans: 0.44 mol
  3.   Ans:  10 mol
  4.   Ans:  4 mol
  5.  Ans:  0.1 mol

Calculate the number of particles specified in the following exercises:

  1. Ans: 6.022 × 1022 atoms
  2. Ans: 1.204 × 1025 atoms
  3.  Ans: 6.022 × 1022 molecules
  4. Ans: 1.806× 1024 molecules
  5. Ans: 1.806 × 1023 atoms