29. In an eighth-grade science class, there are four lab groups. Group 4 designs an experiment to find out how light affects the germination rate of radish seeds. The students in Group 4 write out their procedure and
conduct their experiment. They discover inconsistencies in their data and decide to increase the number of
trials to obtain multiple data sets. Which of these most accurately describes how this should be done?
O Group 4 should repeat their procedure at least three times.
O Group 4 should repeat a revised procedure at least three times.
O Group 4 should communicate their procedure to another group for replication.
O Group 4 should communicate a revised procedure to another group for replication.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

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