Question 858517
{{{ .72*3 = 2.16 }}} = liters of sodium hydroxide
in 72% solution
{{{ .32*8 = 2.56 }}} liters of sodium hydroxide
in final solution
{{{ 2.56 - 2.16 = .4 }}} liters of sodium hydroxide
to be added
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Let {{{ x }}} = liters of solution to be added
{{{ 2.56 / ( 3 + x ) = .32 }}}
{{{ 2.56 = .32*( 3 + x ) }}}
{{{ 2.56 = .96 + .32x }}}
{{{ .32x = 1.6 }}}
{{{ x = 5 }}}
and
{{{ .4/5 = .08 }}}
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5 liters of solution need to be added and
the concentration is 8%
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check:
{{{ 2.56 / ( 3 + x ) = .32 }}}
{{{ 2.56 / ( 3 + 5 ) = .32 }}}
{{{ 2.56 / 8 = .32 }}}
{{{ 2.56 = .32*8 }}}
{{{ 2.56 = 2.56 }}}
OK