Question

How many molecules of Cr2S3 will be made when 3.5(40)²⁴ molecules of S8 are reacted?
Cr + S8 --> Cr2S3

Answer 1

$Cr + S_8 \to Cr_2S_3$

The balanced equation to the equation above is;

$16Cr + 3S_8 \to 8Cr_2S_3$

From the balanced equation above,

3 molecules of Sulphur produces 8 molecules of Chromium Sulfide

3.5(40)²⁴ molecules of sulphur produces x molecules of Chromium Sulfide

x = $\dfrac{3.5×40²⁴×8}{3}$molecules = 9.3 × 40²⁴ molecules

This means that 9.3(40)²⁴ molecules of $Cr_2S_3$ will be made when 3.5(40)²⁴ molecules of $S_8$ are reacted.