Question

A and B react according to the scheme 2A + B  C. The reaction is highly exergonic, that is, it goes to completion when A and B are allowed to react. In order to achieve the exact stoichiometry, your intention is to mix in a kettle 2.000 tons of A and 1.000 ton of B. A balance, the maximum capacity of which is 0.500 tons with 1% precision was used to weigh A and B. Assume that the molar masses of all chemical species are equal. What is the maximum possible amount of unreacted reactants?

Answer 1

0.03 tons

Step-by-step explanation:

From the given information, for every 0.500 tons of A and B, the maximum amount on weighing them will be:

1% of 0.5 = 0.005

Thus, for 2 tons of A; we have:

0.005 × 4 = 0.02

and, for 1 ton of B; we have:

0.005 × 2 = 0.01

However, after taking the precision into account;

The number of tons of A that reacted is = (2 - 0.002) = 1.98 tons of A

The number of tons of B that reacted is = ( 1 - 0.01) = 0.99 tons of B

So, 1.98 tons of A reacted with 0.99 tons of B to form 0.99 tons of C.

∴

For unreacted reactants, The maximum possible amount is (0.02 + 0.01) tons = 0.03 tons