4FeCr2O7+ 8K2CO3 + 1 O22Fe2O3+ 8K2CrO4 + 8CO2

(a) How many molesof FeCr2O7are required to produce 44 molesof CO2?

(b) How many moles of O2are required to produce 107.9 molesof Fe2O3?

(c) If 309 molesof FeCr2O7react, how many molesof O2will be consumed?

1. 22 moles of FeCr2O7

2. 53.95 moles of O2

3. 77.25 moles of O2

Explanation:

4 FeCr2O7+ 8 K2CO3 + 1 O2> 2 Fe2O3+ 8 K2CrO4 + 8 CO2

1. How many moles of FeCr2O7 are required to produce 44 moles of CO2?

Equate the moles of the compounds in the question

4 moles of FeCr2O7 produces 8 moles of CO2

(44 *4 / 8) moles of FeCr2O7 will produce 44 moles of CO2

= 44 *4 / 8

= 22 moles

2. How many moles of 02 is required to produce 107.9 moles of Fe2O3?

1 mole of O2 = 2 moles of Fe2O3

(107.9 *1 / 2) moles of O2 will be required to produce 107.9 moles of Fe2O3

= 107.9 * 1 / 2

= 53.95 moles

3. The ratio of moles for FeCr2O7 to O2 in the reaction is

4 : 1

309 : x ; solve for x

x = 309 * 1 / 4

x =77.25 moles of O2

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.