Lol

four students measure the length of a block of wood. the block has a length of 4.0 cm. the measurements taken by the students are given below.

student a: 3.9 cm
student b: 4.0 cm
student c: 4.1 cm
student d: 3.9 cm

the student's measurements show

a high degree of precision
a high degree of accuracy
both a high degree of precision and a high degree of accuracy
neither accuracy nor precision

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