In a first-order reaction. let's suppose that a quantity, x, of
reactant is added at regular intervals of time, [delta t]. at first
the amount of reactant in the system builds up; eventually, however,
it levels off at a "saturation vlaue" given bythe expression:
saturation value = x/1-10(negative a) , where a = 0.30
deltat/half life.
this analysis applies to prescription drugs, where you take
acertain amount each day. suppose you take 0.100 g of a drugthree
times a day and that the half-life for elimination is 2.0days. (a)
using this equation, calculate the mass of the frugin the body at
saturation (the saturation value). (b) suppose further that side
effects show up when 0.500 g of the drugaccumulates in the body. as
a health-care professional, whatis the maximum dosage you could
assign to a patient for an 8-hourperiod without the
side-effects?

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

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.