Iron(II) can be oxidized by an acidic K2Cr2O7 solution according to the net ionic equation: Cr2O7 2- +6Fe2+ + 14H+>2Cr3+ + 6Fe3+ + 7H20
If it takes 40.5 mL of 0.0250 M K2Cr2O7, to titrate 25.0 mL of a solution containing Fe2+, what is the molar concentration of Fe2+ in the original solution?

a corroding iron, if that's one of your choices

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

plasma - state of matter made up of electrically charged particles