Question

5. 93 grams of copper reacts with 44 grams of hydrochloric acid to produce 39 grams of copper (II) chloride and hydrogen gas. How many grams of hydrogen gas were produced? Include the balanced skeleton equation and a math equation and show all work. inpotenct Sceeuu 3A Uhiush

Answer 1

We know that,

Molar mass of Copper (II) chloride (CuCl_​​​2) = 134.45g/mol

Molar mass of Hydrogen (H_{​​​​​​2})= 2.01g/mol

Number of moles = mass/Molar mass

and

Mass = (number of moles)(molar mass)

Given Value,

Mass of Copper (II) chloride = 39g

Step(1) Calculation for number of moles of CuCl_​​​2.

Number of moles of CuCl_​​​2 = mass of CuCl_​​​2 /molar mass of CuCl_​​​2

Number of moles of CuCl_​​​2 = 39g/(134.45g/mol)

Number of moles of CuCl_​​​2 = 0.29mol.

step (2) Calculation number of moles of H_{​​​​​​2}

balance chemical reaction is given as follows

Cu(s) + 2HCl(l) ----------> CuCl_​​​2 (aq) + H_{​​​​​​2} ​​​​​​(g)

From the stoichiometry of balance chemical reaction.

When one mole CuCl_​​​2 is formed in this chemical reaction, one mole of H_{​​​​​​2} is formed along with CuCl_​​​2.

hence,

When 0.29 mole of CuCl_​​​2 is formed in this chemical reaction, 0.29 mole of H_{​​​​​​2} will be formed with CuCl_​​​2.

Number of moles of H_{​​​​​​2} = 0.29mol

step(3) Calculation for mass of H_{​​​​​​2 ^gass}

mass of H_{​​​​​​2} = (number of moles of H_{​​​​​​2} )(molar mass of H_{​​​​​​2} )

Mass of H_{​​​​​​2} = (0.29mol)(2.01g/mol)

Mass of H_{​​​​​​2} = 0.583g