Question

Calculate the relative molecular masses (or molecular weights) of the following compounds:
${ }$
①$\:\sf{Cane\:sugar,\:C_12 H_22 O_11}$
②$\:\sf{Copper\:sulphate\:crystals,\:CuSo_4 .5H_2 O}$
③$\:\sf{Ammonium\:Sulphate,\:(NH_4 )_2 So_4}$
${ }$
Given that the relative atomic masses (in amu) of Cu = 63.5, S = 32, O = 16, N = 14 and C = 12.
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Answer 1

≽ Question ①

• Cane sugar, C₁₂ H₂₂ O₁₁

We know,

★ C = 12 ; H = 1 ; O = 16

Now, putting the Value :

➣ 12 ༝ 12 + 1 ༝ 22 + 16 ༝ 11

➣ 144 + 22 + 176

➣ 342 amu

• Hence, the relative molecular mass of cane sugar is 342 amu.

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≽ Question ②

• Copper sulphate crystals, CuSo₄ .5H₂O

We know,

★ Cu = 63.5 ; S = 32 ; H = 1 ; O = 16

Now, putting the Value :

➣ 63.5 + 32 + (16 ༝ 4) + 5(2 + 16)

➣ 159.5 + 90

➣ 249.5 amu

• Hence, the relative molecular mass of Copper sulphate crystals is 249.5 amu.

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≽ Question ③

• Ammonium sulphate, (NH₄)₂SO₄

We know,

★ N = 14 ; H = 1 ; S = 32 ; O = 16

Now, putting the Value :

➣ 14 ༝ 2 + 1 ༝ 8 + 32 + 16 ༝ 4

➣ 28 + 8 + 32 + 64

➣ 132 amu

• Hence, the relative molecular mass of Ammonium sulphate is 132 amu.

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✠ Know More :

• ➼ The relative molecular mass (or molecular weight) of an element or a compound is the number that represents how many times one molecule of the substance is heavier than 1/12 of the mass of an atom of carbon - 12.

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Answer 2

Calculate the relative molecular masses (or molecular weights) of the following compounds:

${ }$

①$\:\sf{Cane\:sugar,\:C_12 H_22 O_11}$

②$\:\sf{Copper\:sulphate\:crystals,\:CuSo_4 .5H_2 O}$

③$\:\sf{Ammonium\:Sulphate,\:(NH_4 )_2 So_4}$

${ }$

Given that the relative atomic masses (in amu) of Cu = 63.5, S = 32, O = 16, N = 14 and C = 12.

Calculate the relative molecular masses (or molecular weights) of the following compounds:

${ }$

①$\:\sf{Cane\:sugar,\:C_12 H_22 O_11}$

②$\:\sf{Copper\:sulphate\:crystals,\:CuSo_4 .5H_2 O}$

③$\:\sf{Ammonium\:Sulphate,\:(NH_4 )_2 So_4}$

${ }$

Given that the relative atomic masses (in amu) of Cu = 63.5, S = 32, O = 16, N = 14 and C = 12.