For the reaction: H2(g) + Cl2(g) �¨ HCl(g) (is this balanced?) calculate the mass, in grams of H2 needed to react with 25.0g Cl2.
A. none of these
B. 25.0
C. 0.711
D. 0.353
To determine if the given chemical equation is balanced, we need to ensure that the number of atoms of each element is equal on both sides of the equation.
The balanced equation for the reaction between H2 and Cl2 to form HCl is:
H2(g) + Cl2(g) → 2HCl(g)
In this balanced equation, there are two moles of HCl produced for every one mole of H2 reacted.
To calculate the mass of H2 needed to react with 25.0g Cl2, we can use the stoichiometry of the balanced equation.
First, we need to convert the mass of Cl2 to moles using the molar mass of Cl2.
The molar mass of Cl2 = 35.45 g/mol × 2 = 70.90 g/mol
Moles of Cl2 = mass of Cl2 / molar mass of Cl2 = 25.0 g / 70.90 g/mol = 0.353 mol Cl2
According to the balanced equation, 1 mole of H2 reacts with 1 mole of Cl2. So, the number of moles of H2 needed is also 0.353 mol.
Finally, we can convert the moles of H2 to grams using the molar mass of H2.
Molar mass of H2 = 1.01 g/mol × 2 = 2.02 g/mol
Mass of H2 = moles of H2 × molar mass of H2 = 0.353 mol × 2.02 g/mol = 0.711 g
Therefore, the mass of H2 needed to react with 25.0 g Cl2 is 0.711 g.
The correct answer is C. 0.711 grams.