PLEASE HURRY :how many hydrogen atoms are in 4.56g of water?

≈

1.2

⋅

10

24

 atoms of hydrogen

Explanation:

Water has a molar mass of  

18.01528

g/mol

≈

18

g/mol

.

So, in  

18

g

of water, there will be

18

g

18

g

/mol

=

1

mol

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