Answer to Question #91497 in General Chemistry for Andi Flick

Question

Which reaction will form products that are more stable than the reactants?

A- 2AlBr3+3Zn= 3ZnBr2+2Al
B- CaBr2+2Na=2NaBr+Ca
C- MgBr2+H2= 2HBr+ Mg
D- BaBr2+Ca= CaBr2+Ba
E- 2LiBr+Ba= BaBr2+ 2Li

Answer 1

None of them. According to the activity metal series, only an ion which is higher up in the chart can displace another ion in the salt. Here are all the examples where reactants are more stable than products.

However, there is a little concern about Na and Ca. There are different positions of these metals in different charts if you google it. But according to calculation of electromotive forces, Ca has lower value, so it would displace Na in reaction B (in the given example).

Reference: World Journal of Chemical Education. 2014, 2(2), 21-25 doi:10.12691/wjce-2-2-1.

See also a pic attached.