Question

Someone please help me it’s an assessment on Stochiometry

Answer 1

Answer:

2) 0.3787moles

3) 198g

4) 7.658g

5)  12.26g

Explanation:

2)

2C6H6 + 9O2 -> 12CO2 + 6H20

Weight of a CO2 Mol 12+ 16x2 = 44g

In 100g number of moles = 100/44= 2.2727 Moles

Number of C6H6 2moles burned when creating 12 moles of CO2

Therefore 2.2727/12 x 2 = 0.3787

3)  

3H2SO4 + 2Al(OH)3 -> Al2(SO4)3 + 6H2O

H2O weight of a 1mol is = 2+16 = 18g

2moles of Al(OH)3 cerates 6 moles of water.

3moles of sulfuric creates 6 moles of water.

5.5moles Al(OH)3 reacts with 5.5 moles of sulfuric

Therefore number of water moles = 5.5/3 x 6 = 11moles

Weight water = 11 x 18 = 198g

4)  

Cu + 2AgNO3 -> 2Ag + Cu(NO3)2

1mol of Cu produces 2moles of silver

Ag = 107.86 g/Mol

Cu = 63.54 g/Mol

In 26g Ag number of moles = (26/107.86)/2 x 63.54 = 7.658g

5)

3K2CrO4 + 2AlPO4 -> 2K3PO4 + Al2(CrO4)3

K2CrO4 = 39x2 + 52 + 16x4 = 194g/Mol

Al2(CrO4)3 = 54 + 354 = 408g/Mol

3moles of K2CrO4 creates 1mol of Al2(CrO4)3

Therefore weight of the Al2(CrO4)3 produced by 17.5g potassium chromate

(17.5/194)/3 moles of Al2(CrO4)3 produced  = 0.03moles

Al2(CrO4)3 produced = 0.03 x 408 = 12.26g