1. If you have 5g of pennies how many dozen pennies do you have?

15.69 dozen

Explanation:

Mass of penny = 5 g

Dozens of penny =..?

Next, we shall convert 5 g to gross. This can be obtained as follow:

3824 g = 1000 gross

Therefore,

5 g = 5 g × 1000 gross / 3824 g

5 g = 1.3075 gross

Thus, 5 g is equivalent to 1.3075 gross.

Finally, we convert 1.3075 gross to dozen. This can be obtained as follow:

1 gross = 12 dozen

Therefore,

1.3075 gross = 1.3075 gross × 12 dozen / 1 gross

1.3075 gross = 15.69 dozen

Thus, 5 g of penny is equivalent to 15.69 dozen

b.

the accuracy of the data.

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