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 potassium chlorate was 240 grams, which of the following calculations can be used to determine the mass of oxygen gas formed? (240 × 2 × 31.998) ÷ (122.5 × 3) grams (240 × 3 × 31.998) ÷ (122.5 × 2) grams (240 × 2 × 122.5) ÷ (31.998 × 3) grams (240 × 3 × 122.5) ÷ (31.998 × 2) grams

(240 × 3 × 31.998)/(122.5 × 2)   g

Step-by-step explanation:

We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

M_r:          122.5                31.998

               2KClO₃ ⟶ 2KCl + 3O₂

Mass/g:     240  

Mass of O₂ = 240 g KClO₃ × (1 mol KClO₃/122.5 g KClO₃) × (3 mol O₂/2 mol KClO₃)  × (31.998 g O₂/1 mol O₂) = 94.0 g O₂

Mass of O₂= (240 × 3 × 31.998)/(2 × 122.5) = 94.0 g O₂

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.