How many moles of sodium are needed to produce 2.4 mol of sodium oxide?

Explanation:

4

N

a

+

O

2

→

2

N

a

2

O

.

By the stoichiometry of this reaction if 5 mol natrium react, then 2.5 mol

N

a

2

O

should result.

Explanation:

The molecular mass of natrium oxide is

61.98

g

⋅

m

o

l

−

1

. If

5

m

o

l

natrium react, then

5

2

m

o

l

×

61.98

g

⋅

m

o

l

−

1

=

154.95

g

natrium oxide should result.

So what have I done here? First, I had a balanced chemical equation (this is the important step; is it balanced?). Then I used the stoichiometry to get the molar quantity of product, and converted this molar quantity to mass. If this is not clear, I am willing to have another go.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds