wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

MnO2 on ignition converts into Mn3O4. A sample of pyrolusite having 75%MnO2,20% inert impurities and rest water is ignited in air to constant weight. What is the percentage of Mn in the ignited sample?

A
24.6%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
37%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
55.24%
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
74.05%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 55.24%
Let the weight of sample be xg. Then, weight of MnO2 is 0.75xg.
Moles of MnO2=0.75x87.
Weight of Mn=0.75x87×55=0.474x.
3MnO2Mn3O4+O2.
Weight of Mn3O4 produced=0.75x87×13×229=0.658xg.
Total weight of residue=0.658x+0.2x (weight of impurities).
% of Mn in residue =0.474x0.858x×100=55.24.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Mole Concept
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon