A student heats a 2.5 g sample of calcium carbonate in a test tube. What mass of calcium oxide remains in the test tube when the reaction is complete? CaCO3(s) = CaO(s) + CO2(g)

Select one:
a. 1.4 g CaO
b. 2.1 g CaO
c. 2.5 g CaO
d. 1.0 g CaO

1.4 g CaO

Explanation:

Given data:

Mass of calcium carbonate = 2.5 g

Mass of Cao remain in tube = ?

Solution:

Chemical equation:

CaCO₃    →     CaO + CO₂

Number of moles of CaO:

Number of moles = mass/molar mass

Number of moles = 2.5 g/ 100 g/mol

Number of moles = 0.025 mol

now we will compare the moles of CaO with CaCO₃.

                    CaCO₃        :          CaO

                        1              :             1

                    0.025         :         0.025

Mass of CaO:

Mass = number of moles × molar mass

Mass = 0.025 mol × 56 g/mol

Mass = 1.4 g

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.

a) the particles of the chair are strongly held together.