The drain cleaner Drainex contains small bits of aluminium which react with caustic soda to produce hydrogen What volume of hydrogen at `20^(@)C` aand one bar will be released when `0.15 g` of aluminium reacts ? .

Options

A. 204 mL
B. 200 mL
C. 203 mL
D. 400 mL

Answer

C

Explanation

The reaction between aluminium and caustic soda is
`2A1+2NaOH+2H_(2)Oto2NaA1O_(2)+3H_(2)`
`3xx22.4 " ""L at STP"=2xx27=54`g
`:.` 54 g of A1 produces`H_(2)` "at STP"`=3xx22.4` L
0.15 g of A1 produces `H_(2)` at STP
`=(3xx22.4)/(54)xx0.15`=0.186 L
`{:("At STP"," Given conditions"),(P_(1)=1 "atm" , " "P_(2)=1 "bar"=0.987 "atm"),(V_(1)=0.186 L," "V_(2)=?),(T_(1)=273 "K"," "T_(2)=273+20=293 "K"):} `
Applying ideal gas equation , `(P_(1)V_(1))/(T_(1))=(P_(2)V_(2))/(T_(2))`
`(1xx0.1867)/(273)=(0.987xxV_(2))/(293)`
`V_(2)=(293)/(0.987)=(1xx0.1867)/(273)=0.2030 L=203` mL