Question

By decomposition of 25g of CaCO3,the amount of CaO produced will be .............

a. 2.8g b. 8.4g
c. 14.0g c. 28.0g

Answer 1

Answer:

The mole ratio of the equation is 1:1:1 This is 1 mole of CaCO3 yields 1 mole of Cao and 1 mole of CO2

so we have to calculate the moles of CaCO3:

moles=mass/molar mass

moles=5/100

         =0.05 moles

so this means that the moles of the Cao produced 0.05 moles

mass=moles*molar mass

        =0.05*56

        =2.8 grams

Answer 2

Dear Student,

◆ Answer -

(c) 14 g

◆ Explaination -

Thermal decomposition of calcium carbonate is as follows -

CaCO3 --> CaO + CO2

Here, 1 mol of CaCO3 gives 1 mol of CaO. Hence,

n(CaCO3) = n(CaO)

W(CaCO3)/M(CaCO3) = W(CaO)/M(CaO)

25/100 = W(CaO)/56

W(CaO) = 56/4

W(CaO) = 14 g

Hence, mass of CaO produced is 14 g.

Hope this was useful...