Question

True or False:

A. When atoms bond covalently energy is released

B. All the carbon to carbon bonds in benzene are the same.

C. A mole of NH3 and a mole of H2O weigh the same.

D. ice is denser than liquid water.

E. In organic compounds C atoms have 4 covalent bonds.

F. Water is a nonpolar compound.

G. Diamond, graphite, and fullerene are all forms of carbon.

H. All spontaneous chemical reactions are exothermic.

I. C4H8 is a saturated compound

J. When liquid water freezes heat is liberated.

Answer 1

A. When atoms bond covalently energy is released. True

Because energy of newly formed molecule is lower than the energy of parent atoms.

B. All the carbon to carbon bonds in benzene are the same. True

Due to resonance between single and double bonds, all bonds are same.

C. A mole of NH3 and a mole of H2O weigh the same. False

Because molar mass of NH3 is 17.03 g/mol and molar mass of H2O is 18.01 g/mol.

D. ice is denser than liquid water. False

Because in liquid water, molecules are more closer to each other since one molecule connects to approx. 3.4 other water molecules. But in case of ice, each molecule is bonded to 4 other water molecules. So there is more space between the molecules.

E. In organic compounds C atoms have 4 covalent bonds. True

Because valency of carbon is 4

F. Water is a nonpolar compound. False

Due to bent shape of water, it becomes polar.

G. Diamond, graphite, and fullerene are all forms of carbon. True

These all are allotropes of carbon

H. All spontaneous chemical reactions are exothermic. False

Because spontaneity depends on Gibbs Free energy instead of enthalpy.

I. C4H8 is a saturated compound. False

C4H8 is butene and saturated compounds are those which contains all single bonds.

J. When liquid water freezes heat is liberated. True