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1) Balance the equation below

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1) Balance the equation below. (Hint: do not break apart the polyatomic ions, balance them whole) 

Cu (s) + HNO3 (aq) → Cu(NO3)2 (aq) + NO2 (g) + H2O (l) 


 

 

 

2) Find the mistake in the balancing of the chemical reaction below, and fix it. 

2 Fe (s) + 3 O2 (g) → 2 Fe2O3 (s) 

Molar Conversions 


3) What is the molar mass for each of the following compounds? 


CH4 Molar mass: _________________________________ 


Al2O3 Molar mass: _________________________________ 


Mg(NO3)2 Molar mass: _________________________________ 

 

 

 

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4) How many moles (mol) are in a sample containing 9.03x1024 molecules of CO2? 




5) How many atoms of oxygen are in 1.25 mol of NaNO3? 




6) How many moles (mol) of O2 are in a 13.5 kg sample? 




7) A sample contains 82.6 mmol of Mg(C2H3O2)2. How many moles (mol) of oxygen are in the 
sample? 




8) How many atoms of carbon are in a 312.5 mg sample of C3H8? 





Stoichiometry: Combining Balanced Chemical Equations and Molar Conversions 




 

 

 

 

 

 

9) Given the following balanced chemical equation, answer the questions below. 

CaCO3 (s) → CaO (s) + CO2 (g) 

a. If you have a 500 mg sample of CaCO3, how many moles (mol) of CO2 can be produced 
by the reaction above? 





b. What mass of CaCO3 (g CaCO3) would need to be reacted to form 2.8 kg of CO2? 






10) Given the following UN-balanced chemical equation, answer the questions below. 

Ag2S (s) + Al (s) → Ag (s) + Al2S3 (s) 



a. If you have 25.6 g of Ag2S and 2.8 g of Al, what mass of silver (g Ag) would you be able 
to produce? (Hint: you need to determine the limiting reactant). 











b. What mass of Al2S3 (g Al2S3) would be produced if 9.886 g Al were reacted with excess 
Ag2S?