Calcium carbonate, CaCO3, decomposes when heated to calcium oxide (Cao) and carbon dioxide (CO2). If 100 g of
calcium carbonate is allowed to decompose, 56 g of calcium
oxide is produced. What mass of carbon dioxide is produced
by the decomposition?

Approx. 80.g

80

⋅

g

Explanation:

We need a stoichiometric reaction that represents the decomposition of calcium carbonate:

C

a

C

O

3

(

s

)

+

Δ

→

C

a

O

(

s

)

+

C

O

2

(

g

)

↑

⏐

And thus calcium oxide and calcium carbonate are present in equimolar amounts:

Moles of calcium oxide

=

44.5

⋅

g

56.08

⋅

g

⋅

m

o

l

−

1

=

0.794

⋅

m

o

l

.

Given the stoichiometry of the reaction, an equimolar quantity of calcium carbonate MUST have been present.

This represents a mass of

0.794

⋅

m

o

l

×

100.09

⋅

g

⋅

m

o

l

−

1

≅

80

⋅

g

In the decomposition reaction, what does the

Δ

symbol represent?

Explanation:

the answer is 303.15 or 303

no, the red giant is the hottest with 2.00.000.000 degrees celsius. while the white dwarf only 25,000 degrees celsius.