In an experiment, potassium chlorate decomposed according to the following chemical equation. kclo3 → kcl + o2 (molar mass of kclo3 = 122.5 g/mol; kcl = 74.55 g/mol; o2 = 31.998 g/mol) if the mass of kcl produced was 180 grams, which of the following calculations can be used to determine the mass of potassium chlorate decomposed? (180 × 2 × 74.55) ÷ (122.5 × 2) grams (180 × 3 × 74.55) ÷ (122.5 × 2) grams (180 × 2 × 122.5) ÷ (74.55 × 2) grams (180 × 3 × 122.5) ÷ (74.55 × 2) grams

The correct option is :

(180 × 2 × 122.5) ÷ (74.55 × 2) grams

Explanation:

Here , mole concept is applied

Balance the equation first, it should be :

(1 mole = Molar mass of the molecule)

( 2 mole = 2 x Molar mass)

This means , if 2 moles of KCl is produced then 2 moles of KClO3 should be decomposed

2 x Molar mass of KCl  is produced = 2 x Molar mass  of KClO3 is decomposed

Molar mass of KCl = 74.55 g/mol(given)

Molar mass of KClO3 = 122.5 g/mol(given)

If,

2 x 74.55 gram KCl = 2  x 122.5 gram KClO3

Then

1 gram of KCl

of KClO3

So , 180 gram of KCl will produce ,

of KClO3

=  295.77 gram

The mass of decomposition of   has been given by grams. Thus option C is correct.

The given chemical reaction is:

For the production of 1 mole of KCl, 1 mole of has to be decomposed.

The mass of KCl produced = 180 grams.

Moles of KCl produced =

Moles of KCl produced = moles

For the production of    moles of KCl the same of   has to be decomposed.

Thus, the moles of   has to be decomposed =    moles

Mass of   has to be decomposed = moles molecular weight

Mass of has to be decomposed =  moles 122.2 grams.

For the production of 2 moles of KCl,   has to be decomposed =

grams.

Thus, the mass of decomposition of   has been given by grams. Thus option C is correct.

For more information about the decomposition reaction, refer to the link:

link