Question

HELP PLZ!!!
CheMisTriCiaNs...
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Perfect Answer = God Will Bless You!! ​

Answer 1

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All the above Question are of the Percentage Composition . I will be doing two of them , the rest will be done on the same basis. The mass percentage of a element in a Compound is given by ,

$\red{\dashrightarrow}\boxed{\sf Mass\% =\dfrac{Mass_{(element\ in \ Compound)}}{Molar\ mass_{(Compound)}} \times 100 }$

$\underline{\underline{\blacksquare\pink{\textsf{ Calculate the \% of Nitrogen in Aluminium Nitride .}}}}$

• Firstly we need to find the molar mass of the compound. The formula of Aluminium Nitride is $\sf AlN$ . And the molecular mass will be 26g + 14g = 40g .
• In the Compound mass of nitrogen atoms is 14g since there's only one atom of N .

$\sf\dashrightarrow \% \ of \ N \ = \ \dfrac{14g}{40g}\times 100 =\boxed{\sf \red{ 34.15\ \% }}$

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$\underline{\underline{\blacksquare\pink{\textsf{ Calculate the \% of Phosphorus in Magnesium pyrophosphate .}}}}$

• We know that the Molecular formula of Magnesium pyrophosphate is $\sf Mg_2P_2O_7$ .So its molecular weight will be , 223 g .
• In the Compound the weight of phosphorus atoms is , 2(31) g = 62 g .

$\sf\dashrightarrow \% \ of \ P \ = \ \dfrac{62g}{223g}\times 100 = \boxed{\sf \red{ 27.80\ \% } }$

All the other questions above can be done by the same Method !

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