Question

1. calculate the molecular mass of methane molecules.

2. calculate the molecular mass of C6H6.

3. calculate the molecular mass of NaOH.

4. calculate the molecular mass of Urea. (NH2CONH2)

5. Mass of 1 atom of an element is 5.8×10^-23g. calculate its atomic mass.​

Answer 1

(a) Molecular mass of methane , (CH4)=12+4=16u.

(b) Molecular mass of ethane , (C2H6)=2×12+6×1=30u.

(c) Molecular mass of ethene , (C2H4)=2×12+4×1=28u.

(d) Molecular mass of ethyne (C2H2)=2×12+2×1=26u.

78.11 g/mol

39.997 g/mol

60.056 g/mol

Answer 2

Answer:

I. ch4=12*1+4=16g/mol

ii. c6h6=12*6+1*6=78g/mol

iii. NaOH=23+16+1=39.997=40g/mol

iv. NH2CONH2=14+2+12+16+14+2=60g/mol

v.

Explanation:

Atomic masses are C=12,H=1,O=16,N=14,Na=23