Question

A 20 cm long cylinder of radius 5cm is filled up with NH3 gas at STP calculate the no. of moles of NH3 in cylinder

Answer 1

Answer:

Step by step explanation:

Given:

• A cylinder vessel is 20 cm long.
• It has a radius of 5cm.
• It is filled with $\sf{NH_3}$ gas.

To Find:

• The number of moles of gas.

Answer:

We know that volume of cylinder is given by πr²h.

$\sf{\implies V_{cylinder}=\pi r^2h }$

$\sf{\implies V_{cylinder}= \dfrac{22}{7}\times(5cm)^2\times 20cm }$

$\bf{\leadsto V _{cylinder}= 1571.42cm^3(approx.)}$

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Now we know that 1cm³ = 1ml.

So , 1571cm³ = 1571ml = 1 .5L ( approx).

Now we can find the number of moles of a gas at STP as ,

$\large{\underline{\boxed{\purple{\bf{\dag n =\dfrac{Volume (in\:L)}{22.4L}}}}}}$

$\sf{\implies n = \dfrac{1.5L}{22.4L}}$

$\bf{\leadsto n = 0.066 moles }$

Hence the required answer is 0.066.