Question

21) Which type of bond is the weakest bond between two atoms:

A) ionic bond

B) covalent bond

D) nonpolar bond

E) hydrogen bond

22) Look at the reaction below, fill in the blank with the correct number in order to balance the reaction:

\(6 \mathrm{CO} 2+6 \mathrm{H} 2 \mathrm{O} \rightarrow \mathrm{C} 6 \mathrm{H} 1206+\)

A) 2

B) 4

C) 6

02

23) Which of the following statements below concerning water is not correct?

A) composed of polar molecules.

B) responsible for most of the mass of humans

C) with low heat capacity:

D) may be used to dissolve many substances, such as \(\mathrm{NaCl}\).

E) contains hydrogen bonds.

24) Substances which can readily dissolve in water are called

A) hydrophobic.

B) hydrophilic.

C) electrolytes.

D) nonpolar

E) None of the answers are correct.

25) Hydrophilic molecules can readily associate with

A) nonpolar molecules.

B) hydrophobic molecules.

C) Water molecules.

D) lipid molecules

E) fat molecules.

26) What would be a good example of a nonpolar molecule?

A) \(\mathrm{NaCl}\).

B) \(\mathrm{O}_{2}\)

C) \(\mathrm{H}_{2} \mathrm{O}_{2}\)

())

Nat

E) HCI

27) Which one has greater concentration of hydrogen ions [H+], a substance with a pH of 5 or a substance with a pH of 4 ?

A) Substance w/ pH 4

B) One w/ PH 5

C) They are both equal

D) Neither, pH has nothing to do w/ 11 concentration. 

E) This question is giving me a headache

28) How are water molecules attracted to each other?

A) by oxygen bonds

B) by hydrogen bonds

C) by ionic bonds

D) by nonpolar covalent bonds

E) by isotopes

Answer 1

21)Option D is the correct answer.

Increasing arrangement of bond strenghth is covalent bond>ionic bond>hydrogen bond>polar bond>nonpolar bond

22)Option C is the correct answer

6 CO2+6 H2O $\rightarrow$ C6H12O6+6 O2

23)Option C is the correct answer.

Water has high specific heat capacity(4.184 J)

Water is composed of polar molecules.60% of adult human mass is composed of water.Water is a universal solvent and it contain hydrogen bond.

24)Option A is correct.

hydrophilic means water loving moleculess and hydrophobic means water repellent molecules.Non polar molecule will not dissolve in water due to their hydrophobic character.Electrolytes are substances when dissolve in polar solvents become electrically conducting solutions.

25)Option C is correct.

Hydrophilic means water loving.Hydrophobic molecules are nonpolar eg,fat or lipid molecules.

26)Option B is correct.

O2 is a non polar molecule due to zero net dipole moment.

NaCl is polar due to ionic bond

HCl is polar because hydrogen atom is partially positively charged and chlorine atom is partially negatively charged.

Na+ is polar due to positive charge

water is also polar because net dipole moment is not zero.

27)Option A is correct

pH =-log[H+]

lesser the pH higher the H+ concentration.

28)Option B is correct.Water contain intermolecular hydrogen bond.