4. Consider the reaction MnO2 + 4HCl  MnCl2 + Cl2 + H2O

If 0.86 mol of MnO2 and 1.32 mol of HCl react, which reagent will be used up first? How many grams of Cl2 will be produced?

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

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)