Question #5715d

Question

2012 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-07-27T15:59:09

(a). $2xx10^22$

(b). $4xx10^22$

(c). $2xx10^22$

(d). $66"mg"$

(a).

$Cu^(2+)+2erarr Cu$

Mass Cu = 2.12g

So moles Cu = $2.12/63.6=0.033$

So no. atoms Cu = $0.033xx6.02xx10^(23)=2.0xx10^22$

(b).

From the above equation 1 mole $Cu^(2+)$ ions require 2 moles of electrons to be discharged.

So no. moles electrons $=0.033xx2=0.066$

So no. electrons $= 0.066xx6.02xx10^(23)=4xx10^22$

(c).

$2H^(+)+2erarr H_2$

So you can see a mole of hydrogen gas also requires 2 moles of electrons to be discharged.

so no. molecules $H_2=2xx10^22$ .

(d).

No. moles $H_2$ = no. moles $Cu =0.033$

$M_rH_2=2.0$

So mass $H_2=0.033xx2=0.066"g"=66"mg"$