What mass of hydrogen is consumed when 587.9 kj of energy is evolved from the combustion of a mixture of h 2(g) and o 2( g)? h 2(g)+0 28)o h 20(; d -285.8 k a. 2.073 g b.0.2412 g oc.4.147 g od.6.162 g oe. 2.131 g

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2

a chemical change results in a new substance being formed; whereas a physical change will result in a different state of matter

explanation: