Determine the empirical formula for the following molecular formulas. a) C_6H_6

Question

Determine the empirical formula for the following molecular formulas. a) C_6H_6 ________ b) C_2H_4O_2 ____ c) C_4H_10O_3 ____ 19. The following formula units consist of monatomic cations and anions. Determine the charge on each ion. a) MgO ____ b) AlBr_3 ____ 20. How many molecules of ammonia (NH_3) are in a sample with a mass of 56.6 g? 21. Dolomite, a type of rock found in some petroleum reservoirs is a mixture of CaCO_3, and MgCO_3. If the mass percent of magnesium in a sample of dolomite is 13.2%, what is the mass percent of calcium in this sample? 22. Refer to the electronegativity table in textbook. Which one of the following statements, if any, is incorrect? A. The electronegativity for noble gases is not defined. B. Fluorine has the highest electronegativity. C. Electronegativity increases as we move to the right and/or up the periodic table. D. Metals have lower values for electronegativity than non-metals. E. None are incorrect. 23. Determine whether the bonding in each of the following diatomics is ionic, polar covalent, or non-polar covalent. a) CIF ____ b) F_2 ____ c) RbF ____ d) HI ____ 24. Identify the type of organic functional group and the molecule's name for the following condensed structural formulas. a) CH_3O (CH_2)_2 CH_3 _____ b) CH_3 CH_2 CHO ____ c) CH_3 CH_2 COCH_2 CH_3 ____ d) CH_3 COOCH_2 CH_3 ____ e) CH_3 CONH_2 ____ f) CH_3 CHCH_3 CH_2 SH ____ g NH_2 CH_2 CH_3 ____

Explanation / Answer

18. Empirical formula represents the simple ratio of constituent atoms in the molecular formula.

a) C6H6 ---Empirical formula is: C1H1 that is CH

b) C2H4O2--------empirical formula is : C1H2O1

c) C4H10O3 -- THERE IS NO COMMON DIVISOR FOR THE GIVEN NUMBER OF ATOMS IN THE MOLECULE.

Hence molecular formula and empirical formula are same.

19.) a) As Mg belongs to IIA group, it loses easily 2 electrons and it attains +2 charge.

O- belongs to VIA group, it gains those two eletrons from Mg and attains -2 charge.

b) As Al belongs to IIIA group, it loses easily 3 electrons and it attains +3 charge.

Br- belongs to VIIA group, it needs an electron to attain nearest inert gas configuration.

Hence its charge is -1.

20) Number of moles of a compound = given mass/its molecular mass

Given mass of NH3 is: 56.6g

Molecular mass of NH3 is : 17g/mol

Hence no.of moles= 56.6g/17g/mol

                              = 3.32 mol

21) Mass% of an element in the given compound is: (its atomic mass/ total mass of the compound )x100

Molecular mass of dolomite : MgCO3.CaCO3 is : 184g/mol     

= (40g/mol/184g/mol)x100

        = 21.7%

22) Al the given statements about electronegativity are correct.

23) a) ClF: both the combining atoms are dissimilar nonmetal atoms.Hence it is polar covalent bond.

b) F2: As F is nonmetal and bothe the atoms are same , hence it is nonpolar covalent bond.

c) RbF: As Rb is a metal atom and the other atom F is nonmetal , hence the bond is ionic.

d) HI: both the combining atoms are dissimilar nonmetal atoms.Hence it is polar covalent bond.

24) a) Ether group is present. The molecule is in the form of ROR'.

b) Aldehyde group is present. The molecule is in the form of RCHO.

c) Ketone group is present. The molecule is in the form of RCOR'.

d) Ester group is present. The molecule is in the form of RCOOR'

e) Amide group is present. The molecule is in the form of RCONH2

f) Thiol group is present. The molecule is in the form of RSH

g) Alkyl amine group is present. The molecule is in the form of NH2R

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.