Question

0.56g of gas Q occupies 448cm^3 at standard temperature and pressure(STP).What is the relative molecular mass of Q?[molar volume of gas at STP=22.4dm^3mol^-1]
A 14
B 28
C 32
D 64
@Abhisar @Somy

Answer 1

@Kainui

Answer 2

@dan815

Answer 3

\(\sf Volume = mole \times STP~ volume\)

this formula is used when you need to find mole, or volume & u have the given condition, such as STP or RTP
so rearranging the formula to make mole as subject
\[\sf mole = \frac{ Volume }{ STP~ volume }\]
you have volume of gas given convert it to dm3 by dividing it to 1000
u r given condition STP = 22.4 dm3
so now find mole

Answer 4

you found the mole now use mole formula
\[\sf mole = \frac{ mass }{ Molecular~mass }\]
rearranging the formula to make molecular mass as subject
\[\sf Molecular ~ mass = \frac{ mass }{ mole }\]
you found the mole
and you are given mass in the q
thus use them and find Molecular mass

Answer 5

\[\frac{ 448cm^3 }{ 22400cm^3 }==0.02mol\]

Answer 6

\[\frac{ 0.56g }{ 0.02mol }=28gmol^{-1}\]

Answer 7

Thnx @Somy

Answer 8

no problem :)