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 ? .

Explanation

`{:(,2A1+,2NaOH+2H_(2)Orarr,2NaA1O_(2),3H_(2)),("Initial moles",(0.15)/(27),-,-,-),("Final moles",-,-,-,(3)/(2)xx(0.15)/(27)):}`
`:.` Moles of `H_(2) = (0.15 xx 3)/(2 xx 27) = 8.33 xx 10^(-3)`
By `PV = nRT, P =1 "bar" = 0.987` atm
`T =20 + 273 =293K`
`0.987 xx V = 8.33 xx 10^(-3) xx 0.082 xx 293`
`V = 0.2099 litre = 202.9 mL` .