Answer:
The mole ratio from D to A is 3:1:1:2.
Step-by-step explanation:
Chemical reaction:
A + B → C + D
Balanced chemical equation
2A + B → C + 3D
This general reaction shows that two mole of reactant A and one mole of reactant B react to form one mole of product C and three mole of product D.
Coefficient with reactants and products:
A 2
B 1
C 1
D 3
thus the mole ratio from D to A is 3:1:1:2.