Question

calculate the molar maas of h2o,co2,ch3

Answer 1

(i) H2O:
The molecular mass of water, H2O
= (2 × Atomic mass of hydrogen) + (1 × Atomic mass of oxygen)
= [2(1.0084) + 1(16.00 u)]
= 2.016 u + 16.00 u
= 18.016
= 18.02 u
(ii) CO2:
The molecular mass of carbon dioxide, CO2
= (1 × Atomic mass of carbon) + (2 × Atomic mass of oxygen)
= [1(12.011 u) + 2 (16.00 u)]
= 12.011 u + 32.00 u
= 44.01 u
CH3
The molecular mass of methane, CH3
= (1 × Atomic mass of carbon) + (3 × Atomic mass of hydrogen)
= [1(12.011 u) + 3 (1.008 u)]
= 12.011 u + 3.024 u
= 15.035 u

Answer 2

hii friend
here your answer is :-

1). CO2

C=12
O = 16
12+16*2
44amu
44gm
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2). H2O

H=1
O=16
1*2+16
18amu
18gm
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3). CH3
C=12
H=1
12+1*3
15amu
15gm

hope it helps you ...THANKS
---jecquiline.