PLEASE I NEED HELP ASAP!!!!

1.)Alex reacts 40.0 grams of substance X with 850 mL of 1.0 mol/L solution of hydrochloric acid. What is the maximum mass of carbon dioxide gas that could be obtained from this reaction?


2.)Jess reacts 25.0 grams of substance X with 40.0 mL of 2.0 mol/L of sodium hydroxide solution. The reaction yielded 2.5 grams of calcium hydroxide. Calculate the theoretical yield of calcium hydroxide and %Yield for the reaction.

Respuesta :

The percent yield of the calcium hydroxide is 84.5%.

What is stoichiometry?

Stoichiometry enables us to obtain the mass of a substance form the equation of the reaction.

The equation of the reaction is;

CaCO3 + 2HCl -----> CaCl2 + CO2 + H2O

Number of moles of X = 40.0 grams/100 g/mol = 0.4 moles

Number of moles of HCl = 850/1000 * 1 M = 0.85 moles

If 1 mole of CaCO3 reacts with 2 moles of HCl

0.4 moles of  CaCO3 reacts with  0.4 moles  * 2 moles/1 mole

= 0.8 moles of HCl

Hence X is the limiting reactant.

The reaction is 1:1 then the amount of CO2  produced is 0.4 moles

Mass of CO2 = 0.4 CO2 * 44 g/mol = 17.6 g

2) The reaction equation is; 2NaOH + CaCO3 --->  Ca(OH)2 + Na2CO3

Number of moles of X = 25.0 grams/100 g/mol =  0.25 moles

Number of moles of NaOH= 40/1000 L * 2 M = 0.08 moles

If 1 mole of X reacts with 2 moles of NaOH

0.25 moles  reacts with   0.25 moles   * 2 moles /1 mole

= 0.5 moles

NaOH is the limiting reactant

2 moles of NaOH produces 1 mole of CO2

0.08 moles of NaOH produces 0.08 moles * 1 mole/2 moles

= 0.04 moles of CO2

Theoretical yield of CO2 =  0.04 moles of CO2 * 74 g/mol = 2.96  g

Percent yield = 2.5 g/ 2.96  g * 100

= 84.5%

Learn ore about percent yield:https://brainly.com/question/17042787

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