If the quantity of metal in a metallic oxide is 60%, what is its equivalent weight?

1 Answer
Aug 13, 2017

Answer:

#"12 g"#

Explanation:

The idea here is that you're looking for the mass of this unknown metal that can combine with #"8 g"# of oxygen, which is what the equivalent mass of the metal tells you in this context.

To make the calculations easier, pick a #"100-g"# sample of this metal oxide. According to its percent composition, this sample will contain

  • #60%color(white)(.)"metal " stackrel(color(white)(color(blue)("100 g sample")aaa))(rarr) " 60 g metal"#
  • #40%color(white)(.)"oxygen " stackrel(color(white)(color(blue)("100 g sample")aaa))(rarr) " 40 g oxygen"#

So, you know that #"60 g"# of this unknown metal combine with #"40 g"# of oxygen, which means that #"8 g"# of oxygen will combine with

#8 color(red)(cancel(color(black)("g oxygen"))) * "60 g metal"/(40color(red)(cancel(color(black)("g oxygen")))) = "12 g metal"#

Therefore, you can say that the equivalent mass of the metal is equal to

#color(darkgreen)(ul(color(black)("equivalent mass of metal in 60% metal oxide = 12 g")))#