I just need to know if I did the problem correctly.

The decomposition of phosphine, a very toxic gas, forms phosphorus and hydrogen in the following reaction:
4PH3(g) → P4(g) + 6H2(g)

If the instantaneous rate of the reaction with respect to PH3 is -0.41 M s-1, what is the instantaneous rate of the reaction?

My Anwser:
-(1/4)*-0.41 = 0.10Ms-1

I think you have too many minus signs there. I would have done (1/4)*-0.41 = - 0.10 M/s

To determine the instantaneous rate of the reaction, we can use the stoichiometry of the balanced equation to relate the rate of decomposition of PH3 to the overall rate of the reaction. The stoichiometric coefficient in front of PH3 in the balanced equation is 4, which means for every 4 moles of PH3 that react, one mole of the overall reaction takes place.

Given that the instantaneous rate of the reaction with respect to PH3 is -0.41 M s-1, we need to divide this rate by the stoichiometric coefficient of PH3 to find the instantaneous rate of the reaction.

Thus, the calculation would be:
Instantaneous rate of reaction = (-0.41 M s-1) / (4) = -0.10 M s-1.

So, you did the problem correctly, and the instantaneous rate of the reaction is -0.10 M s-1.