For the following reaction:

6ClO2 (g) + 3H2O (l) = 5HClO3 (l) + HCl (g)

If a chemist wants to make 55.0 g of HCl, how much ClO2 is needed?

This is a stoichiometry problem. Here is a worked example. Just follow the steps.

http://www.jiskha.com/science/chemistry/stoichiometry.html

To determine the amount of ClO2 needed to produce 55.0 g of HCl, you need to follow these steps:

Step 1: Convert the given mass of HCl to moles.
To convert grams to moles, we divide the given mass by the molar mass of HCl, which is 36.46 g/mol:
55.0 g HCl / 36.46 g/mol = 1.51 mol HCl

Step 2: Use the stoichiometric ratio from the balanced equation to determine the moles of ClO2.
From the balanced equation, the stoichiometric ratio of ClO2 to HCl is 6:1.
Therefore, the moles of ClO2 needed can be obtained by multiplying the moles of HCl by the stoichiometric ratio:
1.51 mol HCl × (6 mol ClO2 / 1 mol HCl) = 9.06 mol ClO2

Step 3: Convert the moles of ClO2 to grams.
To convert moles to grams, we multiply the calculated moles by the molar mass of ClO2, which is 67.45 g/mol:
9.06 mol ClO2 × 67.45 g/mol = 610.7 g ClO2

Therefore, to produce 55.0 g of HCl, approximately 610.7 g of ClO2 is needed.

To determine how much ClO2 is needed to produce 55.0 g of HCl, we can use the balanced chemical equation provided.

The mole ratio between ClO2 and HCl in the reaction is 6:1 (from the balanced equation). This means that for every 6 moles of ClO2, we will produce 1 mole of HCl.

To calculate the amount of ClO2 needed, we'll follow these steps:

Step 1: Calculate the molar mass of HCl.
The molar mass of HCl can be found by adding the atomic masses of hydrogen (H) and chlorine (Cl) together.
HCl = 1.007 g/mol (hydrogen) + 35.453 g/mol (chlorine) = 36.460 g/mol

Step 2: Convert the given mass of HCl to moles.
Using the molar mass of HCl calculated in Step 1, we can convert the given mass of HCl to moles by using the formula:

moles of HCl = mass of HCl / molar mass of HCl
moles of HCl = 55.0 g / 36.460 g/mol ≈ 1.509 mol

Step 3: Use the mole ratio from the balanced equation to find the moles of ClO2.
From the balanced equation, we know that the mole ratio of ClO2 to HCl is 6:1. This means that for every 6 moles of ClO2, we will produce 1 mole of HCl.

moles of ClO2 = (1.509 mol HCl) x (6 mol ClO2 / 1 mol HCl) ≈ 9.054 mol ClO2

Step 4: Determine the mass of ClO2 required.
Using the molar mass of ClO2, we can calculate the mass of ClO2 needed using the following formula:

mass of ClO2 = moles of ClO2 x molar mass of ClO2
mass of ClO2 = 9.054 mol x 67.452 g/mol ≈ 611.47 g

Therefore, approximately 611.47 grams of ClO2 is needed to produce 55.0 g of HCl.