Amy put some salt in a weighing dish. Then she put the weighing dish on a sensitive balance to measure the mass of the salt. She removed the weighing dish from the balance and put it in several similar balances. She recorded the mass each time. Mass 1 Mass 2 Mass 3 Mass 4 Mass 5 5.608 g 5.607 g 5.608 g 5.608 g 5.609 g Amy forgot to subtract the mass of the empty weighing dish from her measurements, and she reported the mass of the salt as 5.608 grams. Amy's measurement of the salt's mass accurate because . Amy's measurement of the salt's mass precise because .

a:

by the combination of an unlimited number of elements

the answer is 303.15 or 303

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