Question #1d3d1

1 Answer
Jan 26, 2018

Answer:

x = 7 Solution follows

Explanation:

From the formula, we can see that the number of oxygen atoms would be 4 + x. The total mass of this oxygen would then be #16 xx (4+x) = 64 + 16x#

In the same way, the mass of the entire compound can be expressed in terms of x, as

#(24.3 + 32.1 + 64.0) + x(2+16)= 120.4+18x#

The fraction of the mass that is oxygen is therefore

#(64 + 16x)/(120.4+18x)#

and because we know the oxygen represents 71.4% of the mass, we can write

#(64 + 16x)/(120.4+18x)=0.714#

Now, solve for x:

#64 + 16x=(120.4+18x)xx0.714#

#64 + 16x=85.97+12.85x#

#3.15x = 21.97#

#x=6.97# which we round off to 7