Mantras chanted for a particular resul

Mantras are chanted for various purposes.
When a person chants a mantra for a particular result then they are called sakâma.
Kâma means  desire.  Sa prefix  gives the  meaning  “with”, that  means  mantra chanting
done  with  desires.  The  scripture accepts such  worship.  In  the  Bhagavat  Gita Lord
Krishna says that the devotees are of four types: arta, artahrti, jignayasu and jñani.
1. Arta is one who is afflicted with troubles,
2. Artharti is one who wants to achieve some ends in life,
3. Jignayasu is one who is actively pursuing for the ultimate knowledge,
4. Jñani is one who has gained the ultimate knowledge.
The scripture accepts that all these  four types of  people ultimately will  reach the  final
beatitude  of  life,  namely  Moksha or  Liberation  or  Enlightenment.  Given  this
background the scripture  feels that there is  nothing wrong in taking to some means to
achieve the ends through prayers. When a person fails to achieve a thing through known
means then he takes to the means called prayer by surrendering to the unseen Universal
Intelligence. Mantra chanting is a prayer and hence can be used for that purpos