Question

From 50mg of hydrogen 24×10²³ molecules are removed then find out remaining no. of moles of hydrogen.

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Answer 1

Answer:

The number of moles remaining after removing 24×10²³ molecules from 50g of hydrogen gas are 21.015 moles.

Explanation:

Given that 24×10²³ molecules are removed from 50g of hydrogen gas

We know that the molar mass of Hydrogen gas is 2g/mol.

Number of molecules present in 50 g of Hydrogen gas = Number of moles × Avogadro number

Therefore, Number of moles  = Given mass / Molar mass

Number of moles = $\frac{50\times 10^{-3}}{2}=25\times 10^{-3} moles$

Number of molecules = $25\times 10^{-3}\times 6.022\times 10^{23}=150.55\times 10^{23} molecules$

The remaining number of molecules of hydrogen, when  24×10²³ molecules are removed = $\left(150\cdot 55\times 10^{23}\right)-\left(24\times 10^{23}\right)$ = $126.55\times 10^{23} molecules$

Number of moles = number of molecules / Avogadro number

Therefore the number of moles remaining = $\frac{126\cdot 55\times 10^{23}}{6\cdot 022\times 10^{23}}=21.015 moles$

Answer 2

Answer:

24 × 10²³ molecules are removed from 150.575 × 10²³ molecules of H₂. Thus, 21 moles of Hydrogen are left.