The two stable isotopes of boron exist in the following proportions: 19.78% 105B (10.01 u) and 80.22% 11 2B (1.01 u). Calculate the average atomic mass of boron.

explanation:

i think option no d is the correct answer

girl imma just put my comment here because i need a couple point okurrttt

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

explanation:

0.07 g/cm³

1.37 g/cm³