Homework Help

How many grams of copper should be mixed with 63 grams of zinc to form an alloy...

user profile pic

nasirjam | Student, Grade 9 | Honors

Posted December 10, 2012 at 12:57 PM via web

dislike 0 like

How many grams of copper should be mixed with 63 grams of zinc to form an alloy containing 55% zinc and 45% copper?

Tagged with math

1 Answer | Add Yours

user profile pic

tiburtius | High School Teacher | (Level 3) Associate Educator

Posted December 10, 2012 at 4:55 PM (Answer #1)

dislike 1 like

`m_("Zn")=63"g"`

`p_("Zn")=55`

To calculate percentage  of zinc in an alloy of mass `m` you would use the following formula

` ` `p_("Zn")=m_("Zn")/m cdot 100`                                                             (1)

But we don't know the mass of alloy, but we do know that it contains `63"g"` of zinc and unknown mass of copper. So we have `m=m_("Zn")+m_("Cu")=63+m_("Cu")` so let's put that into (1)

`55=63/(63+m_("Cu"))cdot100`

`55(63+m_("Cu"))=6300`

`63+m_("Cu")=1260/11`

`m_("Cu")=567/11 "g" approx 51.545455 "g"`

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes