Significant Figures?

Question

(b) Suppose 0.078 mol each of H2 and CO2 are placed in a 1.2 L container. When equilibrium is achieved at 986°C, what amounts of CO(g) and H2O(g), in moles, would be present? [Use the value of K calculated in part (a).]

the answer is 0.04
but is that correct significant figures

Answer 1

No, you need 2 significant figures 0.04 has only 1 significant figure.

hint: always write your number in scientific notation and then you will see how many digits you have:

0.04 = 4 * 10-2 = 1 significant figure.

you need one more.

Answer 2

0.040 is the same number of sig figs as 0.078.