Question

STP তে একটি গ্যাসের 112ml আয়তনের ভর 0.22 gm ঐ নমুনায় কটি অনু আছে? গ্যাস টির মোলার ভর কত?

Answer 1

Given that,

volume of sample = 112 ml

Mass of sample = 0.22 gm

We need to calculate the number of moles

Using formula of number of moles

$N=\dfrac{V}{V_{stp}}$

Where, V = volume of the gas

$V_{stp}$ = volume at STP

Put the value into the formula

$N=\dfrac{0.112}{22.4}$

$N=0.005\ moles$

We need to calculate the molecules in the sample

Using formula for molecules

$1\ mole = 6.022\times10^{24}\ atom/molecules$

$0.005\ moles=6.022\times10^{24}\times0.005$

$0.005\ moles=30.11\times10^{21}\ molecules$

We need to calculate the molar mass of gas

Using formula of molar mass

$M=\dfrac{m}{N}$

Where, m = mass

N  = number of moles

Put the value into the formula

$M=\dfrac{0.22}{0.005}$

$M=44\ g/mol$

Hence, The molar mass of the gas is 44 g/mol

The molecules in the sample is $30.11\times10^{21}\ molecules$