Question

A sample of Na2CO3 contains 6.02×10^23 Na+ ions.The mass of sample is ??

Answer 1

Answer : The mass of sample is, 53 grams.

Explanation : Given,

Number of $Na^+$  ions = $6.02\times 10^{23}$

First we have to calculate the number of formula unit of $Na_2CO_3$.

Number of formula units of $Na_2CO_3$ = $\frac{6.02\times 10^{23}}{2}=3.01\times 10^{23}$

Now we have to calculate the molar mass of $Na_2CO_3$.

Molar mass of $Na_2CO_3$ = $2(23)+12+3(16)=106g/mole$

Now we have to calculate the mass of $Na_2CO_3$.

$6.02\times 10^{23}$  formula units of $Na_2CO_3$ has mass = 106 grams

$3.01\times 10^{23}$  formula units of $Na_2CO_3$ has mass = $\frac{3.01\times 10^{23}}{6.02\times 10^{23}}\times 106=53g$

Therefore, the mass of sample is, 53 grams.