Answer:
26 grams of D will be produced.
Explanation:
The reaction is given by:
A + B -----> C + D
Mass of A reacted = 21 g
Mass of B reacted = 22 g
Mass of C formed = 17 g
Mass of D formed = m =?
According to law of conservation of mass, the total mass of the reactants used is equal to the total mass of the product formed.
Then:
mass of A reacted + mass of B reacted = mass of C formed + mass of D formed
21 + 22 = 17 + m
m = 26 g
<span>Well it depends on percentage by what, but I'll just assume that it's percentage by mass.
For this, we look at the atomic masses of the elements present in the compound.
Cu has an atomic mass of 63.546 amu
Fe has 55.845 amu
and S has 36.065 amu
Since there are 2 molecules of Sulfur for each one of Cu and Fe, we'll multiply the Sulfur atomic weight by 2 to obtain 72.13 amu
So we have not established the mass of the compound in amus
63.546 + 55.845 + 72.13 = 191.521
That is the atomic mass of Chalcopyrite. and Iron's atomic mass is 55.845
So to get the percentage, or fraction of iron, we take 55.845 / 191.521
Which comes out to 29.15% by mass
Mass of the sample is not needed for this calculation, but since the question mentions it I would go ahead and check if the question isn't also asking for the mass of Iron in the sample as well, in which case you just find the 29.15% of 67.7g</span>
<em>Transparent because you can see right through it </em>
I think the correct answer is option A. Pure substances can be considered as compounds. Compounds are molecules made of atoms from different elements held together by chemical bonds. Pure substances are these compounds that exist alone no other substance.
